[Federal Register Volume 80, Number 178 (Tuesday, September 15, 2015)]
[Proposed Rules]
[Pages 55286-55304]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-22885]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R5-ES-2015-0136; 4500030113]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List the New England Cottontail as an Endangered or 
Threatened Species

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list the New England cottontail 
(Sylvilagus transitionalis) as an endangered or threatened species and 
to designate critical habitat under the Endangered Species Act of 1973, 
as amended (Act). After review of the best available scientific and 
commercial information, we find that listing the New England cottontail 
is not warranted at this time. However, we ask the public to submit to 
us any new information that becomes available concerning the threats to 
the New England cottontail or its habitat at any time.

DATES: The finding announced in this document was made on September 15, 
2015.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R5-ES-2015-0136. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, New England Field Office, 70 Commercial 
Street, Suite 300, Concord, NH 03301. Please submit any new 
information, materials, comments, or questions concerning this finding 
to the above address.

FOR FURTHER INFORMATION CONTACT: Thomas R. Chapman, Field Supervisor, 
New England Field Office (see ADDRESSES); by telephone at 603-223-2541; 
or by facsimile at 603-223-0104. If you use a telecommunications device 
for the deaf (TDD), please call the Federal Information Relay Service 
(FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.), requires 
that, for any petition to revise the Federal Lists of Endangered and 
Threatened Wildlife and Plants that contains substantial scientific or 
commercial information that listing the species may be warranted, we 
make a finding within 12 months of the date of receipt of the petition. 
In this finding, we will determine that the petitioned action is: (1) 
Not warranted, (2) Warranted, or (3) Warranted, but the immediate 
proposal of a regulation implementing the petitioned action is 
precluded by other pending proposals to determine whether species are 
endangered or threatened, and expeditious progress is being made to add 
or remove qualified species from the Federal Lists of Endangered and 
Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires 
that we treat a petition for which the requested action is found to be 
warranted but precluded as though resubmitted on the date of such 
finding, that is, requiring a subsequent finding to be made within 12 
months. We must publish these 12-month findings in the Federal 
Register. Until now, making a 12-month finding that listing is 
warranted or not warranted for the New England cottontail was precluded 
by other higher priority national listing actions (71 FR 53756, 
September 12, 2006; 72 FR 69034, December 6, 2007; 73 FR 75176, 
December 10, 2008; 74 FR 57804, November 9, 2009; 75 FR 69222, November 
10, 2010; 76 FR 66370, October 26, 2011; 77 FR 69993, November 21, 
2012; 78 FR 70103, November 22, 2013; 79 FR 72449, December 5, 2014).

Previous Federal Actions

    On December 30, 1982, we published our notice of review classifying 
the New England cottontail as a Category 2 species (47 FR 58454). 
Category 2 status included those taxa for which information in the 
Service's possession indicated that a proposed rule may be appropriate, 
but for which sufficient data on biological vulnerability and threats 
were not available to support a proposed rule at that time. This 
classification remained valid for the species in subsequent review 
publications for animals that occurred on September 18, 1985 (50 FR 
37958), January 6, 1989 (54 FR 554), November 21, 1991 (56 FR 58804), 
and November 15, 1994 (59 FR 58982). In the February 28, 1996, 
candidate notice of review (CNOR) (61 FR 7596), we discontinued the 
designation of Category 2 species as candidates; therefore, the New 
England cottontail was no longer a candidate species.
    On August 30, 2000, we received a petition dated August 29, 2000, 
from the Biodiversity Legal Foundation, Conservation Action Project, 
Endangered Small Animals Conservation Fund and Defenders of Wildlife, 
requesting that the New England cottontail be listed under the Act and 
critical habitat be designated. We acknowledged the receipt of the 
petition in a letter to The Biodiversity Legal Foundation, dated 
September 14, 2000, and stated that, due to funding constraints in 
fiscal year (FY) 2000, we would not be able to begin processing the 
petition in a timely manner. Those funding constraints persisted into 
FY 2001.
    On December 19, 2000, Defenders of Wildlife sent a Notice of Intent 
(NOI) to sue the Service for violating the Act by failing to make a 
timely 90-day finding on the August 2000 petition. On February 8, 2002, 
Defenders of Wildlife sent another NOI to sue in response to the 
Service's failure to make a timely 12-month finding on the August 2000 
petition. On May 14, 2002, we advised Defenders of Wildlife that we 
would begin action on the petition in FY 2002.
    On June 30, 2004, the Service published in the Federal Register a 
90-day finding that the petition presented substantial scientific and 
commercial information indicating that listing the New England 
cottontail as endangered may be warranted (69 FR 39395). We also 
announced the initiation of a status review to determine if listing the 
species was warranted and requested additional information and data 
regarding this species. On September 12, 2006, the Service published a 
finding that the petition presented substantial scientific and 
commercial information indicating that listing the New England 
cottontail as threatened or endangered was warranted, but precluded (71 
FR 53756).

[[Page 55287]]

The Service has annually reviewed the status of the New England 
cottontail and reaffirmed the 2006 finding that listing of the species 
remained warranted but precluded with a Listing Priority Number of 2 in 
our CNORs published in 2007 (72 FR 69034; December 6, 2007), 2008 (73 
FR 75176; December 10, 2008), 2009 (74 FR 57804; November 9, 2009), 
2010 (75 FR 69222; November 10, 2010), 2011 (76 FR 66370; October 26, 
2011), 2012 (77 FR 69993; November 21, 2012), 2013 (78 FR 70103; 
November 22, 2013), and 2014 (79 FR 72449; December 5, 2014).
    Subsequent to the 2006 petition finding, the Service developed a 
national multi-year listing work plan associated with a multidistrict 
settlement agreement with the Center for Biological Diversity and 
WildEarth Guardians (In re Endangered Species Act Section 4 Deadline 
Litigation, No. 1-377 (EGS), MDL Docket No. 2165 (D.D.C. May 20, 
2011)). The work plan represents a systematic process for the Service 
to make determinations as to whether the 250 identified candidate 
species still warrant listing as either threatened or endangered 
pursuant to the Act, and if so, proceed with appropriate rulemakings. 
Conversely, if the Service was to determine that listing of any 
candidate species is no longer warranted, candidate status would be 
withdrawn. Through the aforementioned work plan, we agreed to complete 
a final listing determination for the New England cottontail by 
September 30, 2015. This document constitutes the 12-month finding on 
the August 29, 2000, petition to list the New England cottontail as an 
endangered or threatened species and fulfills the aforementioned 
settlement agreement.
    For additional previous Federal actions, see the New England 
cottontail's species' profile page at: http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A09B.

Species Information

Species Description and Taxonomy
    The New England cottontail (Sylvilagus transitionalis) is a medium-
large-sized cottontail rabbit that may reach 1,000 grams (g) (2.2 
pounds (lb)) in weight and is the only endemic cottontail in New 
England (Bangs 1894, p. 411; Allen 1904, entire; Nelson 1909, pp. 169, 
170-171). Sometimes called the gray rabbit, brush rabbit, wood hare, or 
cooney, it can usually be distinguished from the sympatric (similar, 
but different, species that occur in the same area and are able to 
encounter each other) eastern cottontail (S. floridanus) and snowshoe 
hare (Lepus americanus) by several features. In general, the New 
England cottontail can be distinguished by its shorter ear length, 
slightly smaller body size, presence of a black spot between the ears, 
absence of a white spot on the forehead, and a black line on the 
anterior edge of the ears (Litvaitis et al. 1991, p. 11). Like the 
congeneric (separate species of the same genus) eastern cottontail, the 
New England cottontail can be distinguished from the snowshoe hare by 
its lack of seasonal variation in pelage (mammal's coat consisting of 
fur, hair, etc.) coloration.
    New England and eastern cottontails can be difficult to distinguish 
in the field by external characteristics (Chapman and Ceballos 1990, p. 
106). However, cranial (referring to the skull) differences, 
specifically the length of the supraorbital process (elongated bony 
structure located posterior (behind) to the eye) and the pattern of the 
nasal frontal suture (the junction between the nasal and frontal 
bones), are a reliable means of distinguishing the two cottontail 
species (Johnston 1972, pp. 6-11).
    Prior to 1992, the New England cottontail was described as 
occurring in a mosaic pattern from southeastern New England, south 
along the Appalachian Mountains to Alabama (Bangs 1894, pp. 405 and 
411; Nelson 1909, p. 196; Hall 1981, p. 305). However, Ruedas et al. 
(1989, p. 863) questioned the taxonomic status of Sylvilagus 
transitionalis based upon the presence of two distinct chromosomal 
races (genetically differentiated populations of the same species) 
within its geographic range. Individuals north and east of the Hudson 
River Valley in New York had diploid (a cell containing two sets of 
chromosomes (structure that contains genetic material) counts of 52, 
while individuals west and south of the Hudson River had counts of 46. 
Ruedas et al. (1989, p. 863) stated, ``To date, Sylvilagus 
transitionalis represents the only chromosomally polymorphic taxon 
within the genus Sylvilagus,'' and suggested that the two forms of S. 
transitionalis be described as distinct species.
    Chapman et al. (1992, pp. 841-866) conducted a review of the 
systematics and biogeography of the species and proposed a new 
classification. Based upon morphological variation and earlier 
karyotypic (pertaining to the characteristics of a species' 
chromosomes) studies, Chapman et al. (1992, p. 848) reported clear 
evidence for two distinct taxa within what had been regarded as a 
single species. Accordingly, Chapman et al. (1992, p. 858) defined a 
new species, the Appalachian cottontail (Sylvilagus obscurus), with a 
range south and west of the Hudson River in New York. Thus, the New 
England cottontail (S. transitionalis) was defined as that species east 
of the Hudson River through New England. No subspecies of the New 
England cottontail are recognized (Chapman and Ceballos 1990, p. 106).
    Litvaitis et al. (1997, entire) studied the variation of mtDNA 
(mitochondrial DNA, genetic material inherited from the mother) in the 
Sylvilagus complex occupying the northeastern United States. They found 
no evidence to suggest that hybridization is occurring between the New 
England cottontail and the eastern cottontail that was introduced into 
the New England cottontail's range, supporting the conclusions of 
others that the New England cottontail and the eastern cottontail have 
maintained genetic distinction (Wilson 1981, p. 99). Also, the limited 
variation observed in mtDNA led Litvaitis et al. (1997, p. 602) to 
conclude that the reclassification of S. obscurus as a distinct species 
was not supported. However, the more recent scientific view urges 
caution in interpreting the results of earlier mtDNA-based studies. 
Litvaitis et al. (1997, p. 597) sampled 25 individual S. 
transitionalis/obscurus across 15 locations in a geographic area that 
extended from southern Maine to Kentucky. The number of individuals 
sampled ranged from one to seven per site with a mean sample size of 
1.7 individuals per location (Litvaitis et al. 1997, p. 598).
    Allendorf and Luikart (2006, p. 391) warn that, ``many early 
studies that used mtDNA analysis included only a few individuals per 
geographic location, which could lead to erroneous phylogeny 
inferences'' regarding interpretations of descent and relationship 
among evolutionary species or groups. Furthermore, their analysis 
concentrated on the ``proline tRNA and the first 300 base pairs of the 
control region,'' which represents a relatively small fragment of mtDNA 
that can result in a failure to detect significant genetic 
differentiation when used to delineate taxonomic separation (Litvaitis 
et al. 1997, p. 599; King et al. 2006, p. entire). Strict adherence to 
the requirement of reciprocal monophyly (a genetic lineage where all 
members of the lineage share a more recent common ancestor with each 
other than with any other lineage on the evolutionary tree) in mtDNA as 
the sole delineating criterion for making taxonomic decisions often 
ignores important phenotypic, adaptive, and behavioral differences that 
are

[[Page 55288]]

important (Allendorf and Luikart 2006, p. 392; Knowles and Carstens 
2007, pp. 887-895; Hickerson et al. 2006, pp. 729-739).
    Notwithstanding the analyses discussed above, the results from 
Chapman et al. (1992) have been accepted by the scientific community 
(Wilson and Reeder 2005, pp. 210-211). The Service accepts the 
recognized taxonomic reclassification provided by Chapman et al. 1992 
(p. 848) and concludes that Sylvilagus transitionalis and S. obscurus 
are valid taxa and are two separate species. Consequently, we find that 
the New England cottontail meets the definition of a species, as 
provided in section 3 of the Act, and is a listable entity.
Life History
    The New England cottontail, like all cottontails, is primarily an 
herbivore and feeds on a wide variety of grasses and herbs during 
spring and summer and the bark, twigs, and buds of woody plants during 
winter (Dalke and Sime 1941, p. 216; Todd 1927, pp. 222-228). 
Cottontails are short-lived (usually less than 3 years), with predation 
being the cause of death of most individuals (Chapman and Litvaitis 
2003, p. 118). Reproduction in cottontails begins at an early age with 
some juveniles breeding their first season (Chapman et al. 1982, p. 
96). Litters probably contain three to five altricial (born in an 
underdeveloped state and requiring parental care) young, which are born 
in fairly elaborate nests where they receive maternal care (Chapman et 
al. 1982, p. 96). The number of litters produced by wild New England 
cottontails is unknown, but may attain a maximum of seven, based on the 
number of litters produced by other cottontail species (Chapman et al. 
1982, p. 96). Young grow rapidly and are weaned by 26 days from birth 
(Perrotti, in litt. 2014). Female New England cottontails have a high 
incidence of post partum breeding (ability to mate soon after giving 
birth) (Chapman et al. 1982, p. 96). The reproductive capacity of 
cottontails remains relatively stable across population densities and 
is not believed to be a significant factor in regulating cottontail 
populations. Instead, survival, influenced mainly by predation, is 
believed to be the primary factor in regulating populations (Edwards et 
al. 1981, pp. 761-798; Chapman and Litvaitis 2003, p. 118). 
Consequently, habitat that provides abundant shelter is crucial to 
cottontail abundance (Chapman and Ceballos 1990, p. 96).
Metapopulation Dynamics
    The relationship between habitat and survival of wild New England 
cottontails in New Hampshire was investigated by Barbour and Litvaitis 
(1993, entire). Their study revealed that the survival rate of 
cottontails occupying small patches was lower (0.35) than in larger 
patches (0.69) (Barbour and Litvaitis (1993, p. 325). Subsequent 
research found that by late winter rabbits in smaller patches were 
subsisting on a poorer diet, had lower body weights, were presumably 
less fit, and experienced greater predation rates, most likely as a 
result of the need to forage in areas of sparse cover (Villafuerte et 
al. 1997, p. 148). Based on the poor survival of cottontails on the 
smaller habitat patches, Barbour and Litvaitis (1993, p. 326) 
considered patches less than 2.5 hectares (ha) (less than 6.2 acres 
(ac)) in size to be ``sink habitats'' where mortality exceeds 
recruitment (reproduction and immigration). As a consequence of the 
variable quality of habitat patches and their ability to maintain 
occupancy, New England cottontail populations are believed to function 
as metapopulations; that is, a set of local populations comprising 
individuals moving between local patches (Hanski and Gilpin 1991, p. 7; 
Litvaitis and Villafuerte 1996, p. 686). Therefore, the spatial 
structure of a species' populations in addition to the species' life-
history characteristics must be considered when formulating management 
systems for the species' viability (Hanski 1998, p. 41).
    In metapopulations, population extinction and colonization at the 
patch-specific scale are recurrent rather than unique events (Hanksi 
1998, p. 42). As with many metapopulations, local extinctions in New 
England cottontail populations are likely the result of demographic, 
environmental, and genetic stochasticities (Gaggiotti and Hanski 2004, 
pp. 337-366). For example, New England cottontails exhibit indicators 
of demographic stochasticity influencing local populations, because 
individuals on small patches are predominantly male (Barbour and 
Litvaitis 1993, entire). While there are no examples of genetic 
stochasticity that have led to inbreeding depression, recent analysis 
of gene flow among extant populations of New England cottontails in 
southeastern New Hampshire and Maine revealed evidence of genetic drift 
and population isolation due to geographic distance and fragmentation 
(Fenderson et al. 2014, entire), which may be a predictor of ongoing or 
future effects of genetic stochasticity (Gaggiotti and Hanski 2004, pp. 
347-353).
    Winter snow depth and persistence is an example of a stochastic 
environmental factor that could cause a local extinction. However, we 
recognize that winter severity operates at a regional scale that is not 
easily addressed. Therefore, the most effective means of addressing the 
effects of snow depth and persistence on New England cottontail is to 
ensure (1) representation of population diversity across the historical 
range; (2) resiliency of populations by ensuring enough individuals 
exist at local and patch scales to buffer environmental, demographic, 
and genetic stochasticity; and (3) redundancy of populations, because 
multiple populations will help guard against unexpected catastrophes 
such as disease outbreaks (Shaffer et al. 2002, p. 138). See Fuller and 
Tur (2012, pp. 32-41) for more information about the metapopulation 
dynamics of the New England cottontail.
Habitat Characteristics
    New England cottontails occupy native shrublands associated with 
sandy soils or wetlands and regenerating forests associated with small-
scale disturbances that set back forest succession. New England 
cottontails are considered habitat specialists, as they are dependent 
upon these early successional habitats, frequently described as 
thickets (Litvaitis 2001, p. 466). Suitable habitats for the New 
England cottontail contain dense (approximately greater than 9,000 
woody stems per ha (greater than 3,600 stems per ac)), primarily 
deciduous understory cover (Litvaitis et al. 2003a, p. 879), with a 
particular affinity for microhabitats containing greater than 50,000 
stem-cover units/hectare (ha) (20,234 stem-cover units/acre (ac)) 
(Barbour and Litvaitis 1993, p. 324; Gottfried 2013, p. 20). New 
England cottontails are also associated with areas containing average 
basal area (area occupied by trees) values of 53.6 square meters (m\2\) 
per ha (233.6 square feet (ft\2\) per ac), which indicates that tree 
cover is an important habitat component for the New England cottontail 
(Gottfried 2013, pp. 20-21). In addition to demonstrating a strong 
affinity for habitat patches of heavy cover, New England cottontails 
generally do not venture far from the patches (Smith and Litvaitis 
2000, p. 2134). Smith and Litvaitis (2000, p. 2136) demonstrated via a 
winter experiment using animals in an enclosed pen that, when food was 
not available within the cover of thickets, New England cottontails 
were reluctant to forage in the open, lost a

[[Page 55289]]

greater proportion of body mass, and succumbed to higher rates of 
predation compared to eastern cottontails in the same enclosure. 
Consequently, New England cottontail populations decline rapidly as 
understory habitat thins during the processes of forest stand 
maturation (Litvaitis 2001, p. 467).
    Today, New England cottontail habitats are typically associated 
with beaver (Castor canadensis) flowage wetlands, idle agricultural 
lands, power line corridors, coastal barrens, railroad rights-of-way, 
recently harvested forest, ericaceous thickets comprising Kalmia and 
Rhododendron; invasive-dominated shrublands comprising Rosa multiflora, 
Lonicera spp., and others; forest understories dominated by Smilax 
spp.; and pine barrens (Litvaitis 1993b, p. 869; Tash and Litvaitis 
2007, p. 594). In contrast, eastern cottontails appear to have 
relatively generalized habitat requirements, and although they 
sometimes co-occur with the New England cottontail, they can also be 
found in residential areas, where they utilize lawns and golf courses, 
and in active agriculture areas, where relatively small patches of 
thick cover are insufficient to support New England cottontails 
(Chapman and Ceballos 1990, p. 102).
Range and Distribution

Historical Distribution

    In our previous assessments we described the historical 
distribution of the New England cottontail (71 FR 53756; 72 FR 69034; 
73 FR 75176; 74 FR 57804; 75 FR 69222; 76 FR 66370; 77 FR 69993; 78 FR 
70103; 79 FR 72449) as following the circa 1960 range delineation 
presented by Litvaitis et al. (2006, entire). This range description 
included the area east of the Hudson River in New York (excepting Long 
Island); all of Connecticut, Massachusetts, and Rhode Island; and much 
of Vermont, New Hampshire, and southwestern Maine (Litvaitis et al. 
2006, p. 1191). We have reanalyzed existing information as well as 
previously unavailable information regarding land use and predator 
patterns (see Summary of Information Pertaining to the Five Factors--
Factor A and Factor C, respectively, below). Based on this more 
thorough analysis, we conclude that the 1960 range of the New England 
cottontail was a product of extensive land use changes that led to a 
substantial increase in the availability of habitat and human pressure 
that altered ecological processes (Bernardos et al. 2004, p. 150; Ahn 
et al. 2002, p. 1). For the New England cottontail, these changes led 
to an artificially inflated abundance and distribution (Foster et al. 
2002, p. 1345).
    Lacking a description of the species' distribution prior to this 
range expansion, we relied on information pertaining to the 
distribution of habitat in the pre-European landscape and our 
understanding of the ecological factors (e.g., competition with 
snowshoe hare and eastern cottontail (see Summary of Information 
Pertaining to the Five Factors--Factor C below) related to the species. 
Based on our review, we surmise that the historical distribution of the 
New England cottontail was confined to areas from the Hudson River in 
New York through southern New England to southeastern New Hampshire, 
with occurrences being confined to areas in close proximity to coastal 
areas, perhaps extending no farther inland than 100 kilometers (km) (60 
miles (mi)), with occurrences also found on several offshore islands, 
including Nantucket Island and Martha's Vineyard, Massachusetts, and 
Long Island, New York (Cardoza, pers. comm.. 1999; Nelson 1909, pp. 
196-199; A. Tur, pers. comm., 2015).
    Our full analysis of the historical distribution of the New England 
cottontail can be found at http://www.regulations.gov.

Current Distribution and Status

    For the New England cottontail and other early-successional 
species, abundance and distribution increased with land clearing that 
peaked by the mid-19th century and persisted into the early 20th 
century, but then subsequently declined (Bernardos et al. 2004, pp. 
142-158; Foster et al. 2002, pp. 1345-1346). By the mid-1900s, 
afforestation was progressing, and the abundant shrubby young growth 
that had fostered the expanded distribution of the New England 
cottontail's range was beginning to age. Decreases in the abundance of 
the New England cottontail were reported in the Champlain Valley, which 
may have been attributed to increases in red fox (Vulpes vulpes) or the 
increased mechanization that resulted in ``clean'' farming practices, 
such as drainage of wetlands and the removal of old rail fences that 
had favored shrubby field edges (Foote 1946, p. 37).
    By the 1970s, contraction of the range of the New England 
cottontail was well underway. In Massachusetts, those declines were 
evident by the mid-1950s when Fay and Chandler (1955, entire) 
documented the distribution of cottontails within that State. Declines 
were also reported in Connecticut (Linkkila 1971, p. 15; Johnston 1972, 
p. 17). Jackson (1973, p. 21) conducted an extensive analysis of the 
distribution of cottontails in northern New England and stated that 
declines were ongoing in Vermont, Maine, and New Hampshire.
    A systematic comprehensive survey consisting of standardized 
sampling units comprising U.S. Geological Survey 7.5-minute topographic 
quarter quadrangles and field collection protocols to determine the 
current distribution of the New England cottontail within its recent 
(1990 to 2004) historical range was conducted during the 2000-2001 
through 2003-2004 winter seasons (Litvaitis et al. 2006, pp. 1190-
1197). The results indicated that the range had declined substantially 
from the 1960 maximum historical distribution, estimated at 90,000 
square kilometers (km\2\) (34,750 square miles (mi\2\)) to 
approximately 12,180 km\2\ (4,700 mi\2\), representing a reduction of 
approximately 86 percent (Litvaitis et al. 2006, p. 1192). Contraction 
of the New England cottontail's distribution occurred primarily toward 
the southern and eastern coastal regions, as well as interior 
landscapes associated with the Hudson, Housatonic, and Merrimack River 
valleys and associated uplands located respectively in New York, 
Connecticut, and New Hampshire (Litvaitis et al. 2006, p. 1193). This 
contraction was attributed primarily to habitat loss and fragmentation 
(Litvaitis et al. 2006, p. 1193). See Summary of Information Pertaining 
to the Five Factors--Factor A below for more information.
    In addition to the observed range contraction, Litvaitis et al. 
(2006, p. 1193) stated that the range had been fragmented into five 
geographic areas, ranging in size from 1,260 to 4,760 km\2\ (487 to 
1,840 mi\2\). These areas and their sizes are: (1) The seacoast region 
of southern Maine and New Hampshire, 3,080 km\2\ (1,190 mi\2\); (2) The 
Merrimack River Valley of New Hampshire, 1,260 km\2\ (490 mi\2\); (3) A 
portion of Cape Cod, Massachusetts, 980 km\2\ (376 mi\2\); (4) Eastern 
Connecticut and Rhode Island, 2,380 km\2\ (920 mi\2\); and (5) Portions 
of western Connecticut, eastern New York, and southwestern 
Massachusetts, 4,760 km\2\ (1,840 mi\2\). These acreage figures, 
however, substantially exceed the actual area occupied by the species 
because the calculations were based on the total area within each 7.5 
minute USGS quadrangle map where one or more sites with an extant 
occurrence of the New England cottontail was recorded, rather than the 
total area of the actual habitat patches.
    Since the 2000 to 2004 comprehensive rangewide survey,

[[Page 55290]]

numerous efforts to determine the presence of New England cottontails 
have been expended throughout the species' range. Because those efforts 
involve wide variation in search intensity and methodology (e.g., fecal 
pellet collection, hunter surveys, live trapping, and road mortality), 
direct comparison with the results of Litvaitis et al. (2006, pp. 1190-
1197) is not appropriate for the purpose of determining trends in the 
species' status. Despite this shortcoming, the results of these various 
survey efforts provide useful information, including the detection of 
New England cottontails in a few notable areas previously considered 
vacant (e.g., Cape Cod National Seashore and Nantucket Island, 
Massachusetts) (Beattie, in litt. 2013; Scarpitti, in litt. 2013). 
However, some biologists involved in these survey efforts conclude that 
the New England cottontail has declined since the early 2000s, 
particularly along the middle Merrimack River valley in New Hampshire, 
extending northward from the City of Manchester to Concord, and in the 
region of northern Rhode Island (Tur, in litt. 2005; Holman et al., in 
litt. 2014; Tefft et al., in litt. 2014).
    Obtaining population estimates for species such as the New England 
cottontail, that are cryptic and subject to wide population 
fluctuations within relatively broad geographic areas occupied by 
similar species, is challenging. Nevertheless, wildlife biologists 
estimated New England cottontail population sizes for each State within 
the species' range by utilizing area-specific information that included 
factors such as the extent of potential habitat, the occurrence of 
sympatric eastern cottontail populations and local New England 
cottontail survey results. When totaled, these 2014 local estimates 
yield a rangewide population estimate of approximately 17,000 
individual New England cottontails, consisting of: (1) Fewer than 100 
rabbits in Rhode Island (Tefft et al., in litt. 2014); (2) 
Approximately 10,000 in Connecticut (Kilpatrick et al., in litt. 2014); 
(3) As many as 4,600 in Massachusetts (Scarpitti and Piche, in litt. 
2014); (4) 700 in Maine (Boland et al., in litt. 2014); (5) 180 or 
fewer in New Hampshire (Holman et al., in litt. 2014); and (6) 
Approximately 1,600 in New York (Novak et al., in litt. 2014).
    Rangewide, some of the occupied areas are quite small and support 
few New England cottontails. For example, two-thirds of the occupied 
habitat patches in Maine are less than 2.5 ha (6.2 ac) in size and are 
considered population sinks (Barbour and Litvaitis 1993, p. 326; 
Litvaitis and Jakubas 2004, p. 41) because these patches do not contain 
the necessary forage and shelter components for long-term occupancy. In 
New Hampshire, more than half of the 23 sites occupied by the New 
England cottontail are less than 3 ha (7.4 ac) (Litvaitis et al. 2006, 
p. 1194). Litvaitis et al. (2006, p. 1194) report that sampled patches 
in eastern Massachusetts, as well as the majority of those constituting 
the largest extant New England cottontail population (western 
Massachusetts, southeastern New York, and western Connecticut), are 
less than 3 ha (7.4 ac), probably supporting no more than three to four 
New England cottontails per site.
    In 2014, State biologists estimated that there was: (1) More than 
180 km\2\ (46,000 ac) of potential habitat in Connecticut (Kilpatrick 
et al., in litt. 2014); (2) Approximately 6 km\2\ (1,500 ac) in Maine 
(Boland et al., in litt. 2014); (3) 1.8 km\2\ (450 ac) in New Hampshire 
(Holman et al., in litt. 2014); (4) 87 km\2\ (21,000 ac) in New York 
(Novak et al., in litt. 2014); and (5) 30 km\2\ (7,600 ac) in Rhode 
Island (Tefft et al., in litt. 2014). Estimates for Massachusetts are 
not available. However, there are several large habitat expanses in 
Massachusetts, such as at the 60 km\2\ (15,000 ac) of unfragmented 
habitat found at the Massachusetts Military Reservation and a 2.4-km\2\ 
(600-ac) or larger patch within Myles Standish State Forest in the 
southeastern part of the State (Scarpitti and Piche, in litt. 2014). 
While these population estimates are encouraging, it is not yet known 
whether they are sustainable due to their current distribution and 
quality of habitat. The population estimates in Connecticut, 
Massachusetts, and New York consist of areas where the species is 
likely secure because the populations are large enough to be self-
sustaining and the habitat supporting those self-sustaining populations 
is being managed to maintain its suitability.

[[Page 55291]]

[GRAPHIC] [TIFF OMITTED] TP15SE15.000

    Summary of Range and Distribution--In summary, the distribution of 
the species at the time of European contact is unknown; however, the 
species was most likely found in greatest abundance in coastal areas 
where shrublands were concentrated and suitable habitat patches are 
presumed to have been relatively large. New England cottontail 
occurrence likely progressively diminished inland where suitable 
habitat patches tend to be smaller and relatively short lived. The 
presence of the snowshoe hare, a potential competitor, along with 
climatic conditions that favor the hare, likely naturally contributed 
to the foreshortened distribution of the New England cottontail. 
However, these natural control processes were disrupted when the land 
use patterns that accompanied European settlement changed. The land use 
patterns altered the abundance and distribution of shrublands, 
particularly in interior New England, and thus artificially inflated 
the amount of suitable habitat available to the New England cottontail. 
This artificial increase in suitable habitat offset the naturally 
controlling factors of climate and competition, thereby allowing the 
New England cottontail to disperse in more northerly and inland 
directions.
    Despite the spatial and temporal gaps in the species' distribution 
records, analysis of the best available information documents the 
changes in the historical distribution of the New England cottontail 
over time. The evidence clearly indicates that the distribution greatly 
increased during the 19th and early 20th centuries, when regionwide 
conversion of mature forest to young forest habitat within the interior 
uplands was at its peak and shifts in snowshoe hare abundance provided 
ample expansion opportunities for the New England cottontail. In the 
case of the Hudson River and Lake Champlain valleys, the best available 
information indicates that over a 107-year period the species extended 
its range northward from Troy, New York, to the Canadian border, a 
distance of approximately 257 km (160 mi), at a rate of approximately 
2.4 km (1.5 mi) per year (Bachman 1837, p. 328; Foote 1946, p. 39). In 
the latter half of the 20th century, harvesting of interior upland 
forests waned, and young forest habitat capable of maintaining New 
England cottontail populations and the distribution of the species 
contracted southward and eastward toward coastal areas. This 
contraction, however, is not representative of the species' pre-
Columbian baseline distribution, because extensive amounts of the 
intervening landscape have been converted to other land uses that have 
degraded habitat for the species and contributed to its currently 
disjunct distribution.
Rangewide Conservation Efforts
    Beginning in 2008, State and Service biologists began organizing a 
conservation effort for the New England cottontail. A governance 
structure was formalized in 2011 to enhance cooperation between the 
Maine Department of Inland Fisheries and Wildlife (MDIFW), the New 
Hampshire Fish and Game Department (NHFGD), the Massachusetts Division 
of Fisheries and Wildlife (MDFW), the Rhode Island Department of 
Environmental Management), the Connecticut Department of Energy and 
Environmental Protection, the New York Department of Environmental 
Conservation, the U.S. Department of

[[Page 55292]]

Agriculture's Natural Resources Conservation Service (NRCS), and the 
Service (hereafter referred to as the Parties). The Parties established 
an Executive Committee, facilitated by the Wildlife Management 
Institute (WMI), and adopted bylaws (Fuller and Tur 2012, p. 4) ``to 
promote recovery, restoration, and conservation of the New England 
cottontail and its associated habitats so that listing is not 
necessary'' (New England cottontail Executive Committee, in litt. 
2011). This Executive Committee comprises high-level agency 
representatives, capable of making staffing and funding decisions.
    The Executive Committee established a Technical Committee, 
comprising staff-level biologists with biological and conservation 
planning expertise, and delegated eight initial charges to advance the 
work of New England cottontail conservation, including preparation of a 
multifaceted conservation strategy with quantifiable objectives to 
measure conservation success (New England cottontail Executive 
Committee, in litt. 2011). The Technical Committee drafted, and the 
Executive Committee approved, the 2012 peer-reviewed Conservation 
Strategy for the New England Cottontail (Conservation Strategy) (Fuller 
and Tur 2012, available at http://www.newenglandcottontail.org 
(accessed March 18, 2015)). This Conservation Strategy describes: (1) 
An assessment of the conservation status of and threats facing the New 
England cottontail; (2) The process used to develop a conservation 
design that includes those landscapes, hereafter referred to as Focus 
Areas, where conservation actions will be taken to achieve a series of 
explicit conservation goals; (3) The objectives related to achieving 
those goals; (4) Important conservation actions needed to protect and 
manage habitat; (5) Communications needed to ensure implementation; (6) 
Research needed to improve understanding of the ecology of the New 
England cottontail; (7) Monitoring techniques to evaluate the 
effectiveness of the implemented actions and identify any changes 
needed to increase their effectiveness; (8) The commitment of the 
participating agencies to carry out the conservation effort; and (9) 
The process for modifying the Conservation Strategy in the future, if 
necessary, in light of any new and relevant information (Fuller and Tur 
2012, p. 4). The Conservation Strategy focuses on securing New England 
cottontail within its current distribution (see figure 1). The 
Conservation Strategy includes an implementation plan through 2030.

Summary of Information Pertaining to the Five Factors

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth procedures for adding species to, removing 
species from, or reclassifying species on the Federal Lists of 
Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of 
the Act, a species may be determined to be endangered or threatened 
based on any of the following five factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms;
    (E) Other natural or manmade factors affecting its continued 
existence.
    In making this finding, information pertaining to the New England 
cottontail in relation to the five factors provided in section 4(a)(1) 
of the Act is discussed below. In considering what factors might 
constitute threats, we must look beyond the mere exposure of the 
species to the factor to determine whether the species responds to the 
factor in a way that causes actual effects to the species. If there is 
exposure to a factor, but no response, or only a positive response, 
that factor is not a threat. If there is exposure and the species 
responds negatively, the factor may be a threat and we then attempt to 
determine how significant a threat it is. If the threat is significant, 
it may drive or contribute to the risk of extinction of the species 
such that the species warrants listing as endangered or threatened as 
those terms are defined by the Act. This does not necessarily require 
empirical proof of a threat. The combination of exposure and some 
corroborating evidence of how the species is likely affected could 
suffice. The mere identification of factors that could affect a species 
negatively is not sufficient to compel a finding that listing is 
appropriate; we require evidence that these factors are operative 
threats that act on the species to the point that the species meets the 
definition of an endangered or threatened species under the Act. 
Although this language focuses on impacts negatively affecting a 
species, section 4(b)(1)(A) of the Act requires us to consider efforts 
by any State, foreign nation, or political subdivision of a State or 
foreign nation to protect the species. Such efforts would include 
measures by Federal agencies, Native American Tribes, businesses, 
organizations, and individuals that positively affect the species' 
status. Also, Federal, Tribal, State, and foreign recovery actions (16 
U.S.C. 1533(f)), and Federal consultation requirements (16 U.S.C. 1536) 
constitute conservation measures.
    Read together, sections 4(a)(1) and 4(b)(1)(A), as reflected in our 
regulations at 50 CFR 424.119(f), require us to take into account those 
factors that either positively or negatively affect a species status so 
that we can determine whether a species meets the definition of 
threatened or endangered. In so doing, we analyze a species' risk of 
extinction by assessing its status (i.e., is it in decline or at risk 
of decline and at what rate) and consider the likelihood that current 
and future conditions and actions will promote or threaten a species' 
persistence by increasing, eliminating, or adequately reducing one or 
more threats to the species. This determination requires us to make a 
prediction about the future persistence of a species.
    In making our 12-month finding on the petition, we considered and 
evaluated the best available scientific and commercial information.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

    The New England cottontail requires thicket habitat and is 
frequently associated with shrublands and other ephemeral stages of 
forest regeneration after a disturbance such as fire, forest insect 
outbreak, timber harvesting, or beaver activity (Litvaitis 2001, p. 
466). Because early successional species require habitats that 
generally persist only for a short time, continual turnover of mature 
forest somewhere on the landscape is necessary for the species to 
maintain its distribution and abundance.
    The amount of early successional forest cover is limited in the 
States where the New England cottontail occurs. Data from the U.S. 
Department of Agriculture indicate that the area of early successional 
forest cover in the southern New England States (Massachusetts, 
Connecticut, and Rhode Island) declined from 36 percent of the total 
timber land area in the early 1950s to 5 percent in the late 1990s 
(Brooks 2003, p. 68). Jackson (1973, p. 21) reported a decline in New 
England cottontails in Vermont, New Hampshire, and Maine, and 
attributed the decline to changes in habitat, primarily to the 
reduction of cover on a landscape scale.

[[Page 55293]]

    Inventories from the U.S. Forest Service reveal that the extent of 
forest in the seedling-sapling stage (thickets favorable to the New 
England cottontail) declined by more than 80 percent in New Hampshire 
from 845,425 ha (2,089,091 ac) to 131,335 ha (324,536 ac) during the 
period 1960 to 1983 (R. Brooks, personal communication, in Litvaitis 
and Villafuerte 1996, p. 689) and by 14 percent in New York from 1980 
to 1993 (Askins 1998, p. 167). While the forest inventory results 
reported by Brooks (2003, p. 68) found an increase in the early 
successional forest component of northern New England States, most of 
the increase occurred in the industrial forest land of northern Maine, 
well north of the historical and current range of the New England 
cottontail. Maine's southernmost counties (York and Cumberland) that 
still support populations of New England cottontails, have experienced 
declines in young forest stands, from about 38 percent in 1971 to 11 
percent in 1995 (Litvaitis et al. 2003b, p. 881). Litvaitis et al. 
(1999, p. 106) reported that remaining shrub-dominated and early 
successional habitats in the northeast continue to decline in both 
coverage and suitability to the wildlife species dependent upon them.
    The decline of early successional forest in the Northeast is 
primarily due to forest maturation (Litvaitis 1993b, p. 870), which is 
a natural process. However, other influences are compounding the 
situation. Habitat destruction and modification are occurring as a 
result of human population growth and development (Brooks 2003, p. 65). 
The three southern New England States, Connecticut (greater than 270 
inhabitants per km\2\ (700 inhabitants per mi\2\)), Rhode Island 
(greater than 380 inhabitants per km\2\ (1,000 inhabitants per mi\2\)), 
and Massachusetts (greater than 300 inhabitants per km\2\ (800 
inhabitants per mi\2\)), which constitute the center of the New England 
cottontail's range, are among the most densely populated areas in the 
United States, with only New Jersey and the District of Columbia being 
more densely populated (U.S. Census Bureau, 2012). Similarly, New York, 
at greater than 150 inhabitants per km\2\ (400 inhabitants per mi\2\), 
ranks eighth among the 50 States in population density, though much of 
this density is centered around a few urban areas, especially New York 
City. Rhode Island is most developed to the east of Narragansett Bay; 
the largest forest patches remain along the less developed western edge 
of the State. Connecticut is most developed in the southwestern corner 
and up the Connecticut River Valley. Notably, the most densely human-
populated areas of Connecticut and Rhode Island are relatively devoid 
of New England cottontails. In association with human populations, 
early successional habitats that once supported New England cottontails 
have been converted to a variety of uses that make them unsuitable for 
the cottontail, thereby contributing to habitat loss and fragmentation 
(Litvaitis et al. 2006, p. 1194). In the Seacoast Region of New 
Hampshire and Maine, the effects of habitat fragmentation are having a 
deleterious effect on remnant populations of the New England 
cottontail, such that enhancing gene flow by improving habitat or 
conducting translocations may be required to maintain populations in 
those landscapes (Fenderson et al. 2014, pp. 1-23). Among shrub-
dominated plant communities, scrub oak and pitch pine barrens that 
provide cottontail habitat have been heavily modified or destroyed by 
development (Patterson 2002, unpublished presentation abstract).
    Litvaitis et al. (1999, p. 106) concluded that shrub-dominated and 
early successional habitat may be the most altered and among the most 
rapidly declining communities in the Northeast. Based on changes in 
human populations and associated development, without intervention, 
this trend will likely continue. For example, U.S. Census Bureau data 
for the New England States indicate a 3.8-percent population growth, 
equating to an increase of 522,348 people, during the period 2000 to 
2010 (U.S. Census Bureau 2011). Analyses of U.S. Census data 
demonstrates that, in 1982, the number of acres developed for every new 
person was 0.68 in New England (http://wrc.iewatershed.com (accessed 
May 2006)), but in 1997, the number of acres developed for every new 
person was 2.33, an almost four-fold increase. Given the 1997 rate of 
development for each additional resident (0.94 ha (2.33 ac) per person) 
and the measured population growth for New England, 491,007 additional 
ha (1.2 million additional ac) of wildlife habitat would have been 
converted and fragmented during the period 2000 to 2010 (adapted from 
U.S. Census Bureau 2011, (http://wrc.iewatershed.com (accessed May 
2006)), and it is highly likely that this included habitat that was 
suitable and supported New England cottontails.
    As an example, The Society for the Protection of New Hampshire's 
Forests (Sundquist and Stevens 1999, p. entire) estimated that New 
Hampshire will lose approximately 80 percent of its forest land to 
various types of development by the year 2020. Further, this analysis 
predicted that the greatest loss of forest lands, approaching 24,281 ha 
(60,000 ac), would occur in the southeastern portion of the State, 
principally in Rockingham, Hillsborough, and Strafford Counties. These 
counties account for all known New England cottontail occurrences in 
the State. In fact, observations by Service biologists in 2005 
confirmed that 2 of the 23 New Hampshire cottontail sites known to be 
occupied at some time from 2001 to 2003 had been lost to development, 
and 5 other sites were posted ``for sale.''
    Noss and Peters (1995, p. 10) consider eastern barrens to be among 
the 21 most endangered ecosystems in the United States. Some eastern 
barrens, such as the pitch pine and scrub oak barrens of Cape Cod, 
Massachusetts, are suitable habitat for the New England cottontail. It 
is unclear to what extent barrens in other States also supported 
occurrences of New England cottontails; however, as of 2014 the barrens 
of southeastern Massachusetts are known to be occupied by the New 
England cottontail (Scarpitti and Piche, in litt. 2014).
    Within the historical range of the New England cottontail, the 
abundance of early successional habitats continues to decline 
(Litvaitis et al. 1999, p. 106; Brooks 2003, p. 65), and for the most 
part, remaining patches are small and located in substantially modified 
landscapes (Litvaitis and Villafuerte 1996, p. 687; Litvaitis 2003, p. 
115; Litvaitis et al. 2008, p. 179). The fragmentation of remaining 
suitable habitats into smaller patches separated by roads and 
residential and other types of development can have profound effects on 
the occupancy and persistence of New England cottontail populations. 
Barbour and Litvaitis (1993, p. 321) found that New England cottontails 
occupying small patches of habitat less than or equal to 2.5 ha 
(approximately 6 ac) were predominantly males, had lower body mass, 
consumed lower quality forage, and had to feed farther from protective 
cover than rabbits in larger patches (5 ha or greater than 12 ac). This 
study also demonstrated that New England cottontails in the smaller 
patches had only half the survival rate of those in the larger patches 
due to increased mortality from predation. Barbour and Litvaitis (1993, 
p. 321) state that the skewed sex ratios (or single occupant) and low 
survival among rabbits on small patches may effectively prevent 
reproduction from occurring on small patches. Due to skewed sex ratios 
and low survival rates, the presence of New

[[Page 55294]]

England cottontails in these small patches is dependent on the 
dispersal of individuals from source populations (Barbour and Litvaitis 
1993, p. 326). Litvaitis et al. (2008, p. 179) and Barbour and 
Litvaitis (1993, p. 321) view these small patches as sink habitats. The 
relationship between winter survival and food resources is supported by 
a 2010 study on eastern cottontail, the results of which could be 
extrapolated to New England cottontail, which concluded supplemental 
feeding of animals in small habitat patches enhanced winter survival 
(Weidman 2010, p. 20).
    Natural or anthropogenic disturbances that create small, scattered 
openings may no longer provide habitats capable of sustaining New 
England cottontail populations because, in contemporary landscapes, 
generalist predators effectively exploit prey restricted to such 
patches (Brown and Litvaitis 1995, p. 1005; Villafuerte et al. 1997, p. 
148). Barbour and Litvaitis (1993, p. 321) concluded that local 
populations of New England cottontails may be vulnerable to extinction 
if large patches of habitat are not maintained. The Service concludes 
this likely explains why 93 percent of the apparently suitable habitat 
patches that were searched by Litvaitis et al. (2006, pp. 1190-1197) 
were found to be unoccupied.
    Human population growth has had another effect, in addition to 
habitat loss and fragmentation, on forests within the New England 
cottontail range. Between 1950 and 2000, the human population increased 
44 percent in southern New England and 71 percent in northern New 
England (Brooks 2003, p. 70). With the increase in human population, an 
increase in the parcelization (i.e., the fragmentation of ownership) of 
northeastern forests into smaller and smaller parcels followed. The 
majority of private northeastern forest owners, excluding industrial 
forest owners, own less than 4 ha (10 ac) each; about 12 percent of 
timberland in the Northeast is publicly owned (Brooks 2003, p. 69). An 
increasingly urbanized landscape, with many small, partially forested 
residential parcels, imposes societal and logistical restrictions on 
forest management options (Brooks 2003, p. 65). Shrublands, clear cuts, 
and thickets are ``unpopular habitats'' among the public (Askins 2001, 
p. 407), and private forest owners are resistant to managing for this 
type of habitat (Trani et al. 2001, p. 418; Kilpatrick et al., in litt. 
2014). Timber harvesting and fire or other disturbance regimes that 
would maintain or regenerate early successional habitat for thicket-
dependent species like the New England cottontail are less likely to 
occur in a landscape with many small landowners.
    Based on computer simulations demonstrating that populations 
dominated by small patches were likely to go extinct (Livaitis and 
Villafuerte 1996, entire), Litvaitis et al. (2006, p. 1194) conclude 
that the five remaining disjunct populations of the New England 
cottontail, as currently configured, do not represent a stable 
condition for long-term persistence. More recently, genetic analysis of 
New England cottontail populations in Maine and Seacoast New Hampshire 
corroborated the negative effects of fragmentation (Fenderson et al. 
2014, pp. 13 and 17). Fenderson et al.'s (2014, p. 17) findings of 
isolated populations with low effective population sizes and low 
genetic diversity suggest that populations in the study area were 
vulnerable to extirpation.
    In summary, the best available information indicates that in parts 
of the species' range, New England cottontails occur on small parcels, 
where food quality is low and winter mortality to predators (see Factor 
C below) is unsustainably high (Barbour and Litvaitis 1993, p. 321; 
Brown and Litvaitis 1995, p. 1005). In contrast, several large habitat 
tracts occur in the Cape Cod area of Massachusetts, western 
Connecticut, and eastern New York, and those populations are likely 
secure (Scarpitti and Piche, in litt. 2014; Kilpatrick et al., in litt. 
2014; Novak et al., in litt. 2014). Further, the current distribution 
of the species is discontinuous, being divided by expanses of 
unsuitable habitat that separate the range into five population 
clusters.
    Among the factors contributing to the long-term and rangewide 
reduction in habitat, habitat succession was considered by Litvaitis 
(1993b, p. 866) to be the most important. However, at a local or 
individual patch scale, loss or modification of habitat due to 
development is also significant. In general, the range of the New 
England cottontail has contracted by 86 percent since 1960 (Litvaitis 
et al. 2006, p. 1190), and current land use trends in the region 
indicate that the rate of change, about 2 percent range loss per year, 
is likely to continue if conservation actions to address the decline 
are not implemented (Litvaitis and Johnson 2002, p. 4; Litvaitis et al. 
2006, p. 1195; Fenderson et al. 2014, p. 17). This is supported by 
results from various State surveys conducted since 2004 (Tefft et al., 
in litt. 2014; Holman et al., in litt. 2014; Boland et al., in litt. 
2014; Kilpatrick et al., in litt. 2014).
Conservation Efforts To Reduce Habitat Destruction, Modification, or 
Curtailment of Its Range
    As described above, the Conservation Strategy (Fuller and Tur 2012, 
entire) guides the New England cottontail's rangewide conservation and 
was specifically developed to consider the species' life-history traits 
or resource needs. These traits commonly include morphological, 
developmental, and behavioral characteristics such as body size; growth 
patterns; size and age at maturity; reproductive effort; mating 
success; the number, size, and sex of offspring; and rate of senescence 
(Ronce and Olivieri 2004, p. 227). Factors addressing habitat quality 
and quantity were also considered. Given the species' life history 
characteristics, the key to its viability is ensuring that ample 
resources are available to support population increases, as opposed to 
maximizing the survival of individuals. In addition, we also recognize 
that the landscape-level alterations occurring throughout the species' 
range have fragmented New England cottontail populations and 
substantially increased the risk of extinction (Litvaitis et al. 2006, 
p. 1195; Fenderson et al. 2014, p. 17).
    The Conservation Strategy (Fuller and Tur 2012, p. 19) contains a 
summary of the information contained in the Service's 2013 Species 
Assessment and Listing Priority Assignment Form (Service 2013, entire) 
and concluded that the primary threat to the species was habitat 
modification resulting, in part, from: (1) Forest maturation; (2) 
Disruption of disturbance regimes that set back succession; and (3) 
Habitat modification, fragmentation, and destruction resulting from 
development (Fuller and Tur 2015, pp. 19, 21-23). The Conservation 
Strategy prescribes forest management practices on public and private 
lands to reverse forest maturation and increase habitat capable of 
supporting the New England cottontail (Fuller and Tur 2012, pp. 20-21) 
and identifies potential landscapes (e.g., Focus Areas) where 
conservation actions would be implemented. The Conservation Strategy 
identified 41 separate Focus Areas distributed across all 6 States 
within the species' current range and containing a total habitat area 
in excess of 20,000 ha (50,000 ac). Each individual Focus Area will 
contain populations ranging from 100 to 2,500 animals, as appropriate 
(Fuller and Tur 2012, p. 30).
    The Conservation Strategy specifies that conservation of the 
species will be achieved by implementing rangewide conservation actions 
that establish:

[[Page 55295]]

    [cir] 1 New England cottontail landscape capable of supporting 
2,500 or more individuals;
    [cir] 5 landscapes each capable of supporting 1,000 or more 
individuals; and
    [cir] 12 landscapes each capable of supporting 500 or more 
individuals.
    Each New England cottontail landscape/Focus Area should comprise a 
network of 15 or more habitat patches, each 10 ha (25 ac) or greater in 
size, and situated within dispersal distance (less than 1 km (0.6 
miles)) to other patches of suitable habitat (Fuller and Tur 2012, p. 
43). This dispersal distance was based on Litvaitis and Villafuerte's 
(1996, p. 689) conclusion that dispersal of New England cottontail fits 
a geometric distribution, with a maximum distance of 3 km (1.9 mi). 
Recent analysis of gene flow confirms the accuracy of this distance, as 
evidenced by Fenderson et al.'s (2014, p. 15) conclusion that New 
England cottontails have difficulty traversing distances greater than 5 
km (3 mi).
    The Conservation Strategy Landscape planning further specifies that 
actions should take into account the habitat matrix (condition of the 
landscape surrounding habitat patches), because areas with numerous 
anthropogenic features or substantial natural barriers are likely to be 
highly fragmented and form barriers to dispersal that may otherwise 
encumber conservation efforts (Fuller and Tur 2012, p. 43). The 
Technical Committee addressed the habitat matrix conditions by building 
in redundancy as expressed in the creation of the 41 Focus Areas--not 
all 41 Focus Areas will be needed to achieve the landscape goals 
specified above. The Conservation Strategy identifies a suite of 
implementation objectives, many of which are intended to reduce the 
threat of habitat destruction, modification, and curtailment of the New 
England cottontail's range (Fuller and Tur 2012, pp. 44-87).
    The Conservation Strategy's 2014 Annual Performance Report 
documents previous and ongoing implementation actions that have and are 
addressing loss of habitat for the New England cottontail (Fuller and 
Tur 2015, entire). For example, by the autumn of 2013, approximately 
14,000 ac (5,666 ha) of habitat were under evaluation or contract for 
appropriate management actions, and by the end of 2014, specific 
habitat treatments were estimated to be complete on more than 6,700 ac 
(2,711 ha) of State, other public, or private land (Fuller and Tur 
2015, p. 55). In addition, more than 10,000 ac (4,047 ha) of self-
sustaining New England cottontail habitat has been identified (Fuller 
and Tur 2015, p. 55). However, although we have evidence of 
demonstrated implementation success, not all of the actions implemented 
have yet to show full effectiveness for the species (see Policy for the 
Evaluation of Conservation Efforts Analysis section below). The 2014 
Annual Performance Report acknowledges that suitable habitat is not 
equally distributed across the Focus Areas and that due to the 
ephemeral nature of most of the species' habitat, additional management 
and maintenance actions are necessary to keep the habitat in suitable 
condition (Fuller and Tur 2015, p. 55).
    Summary of Factor A--We identified a number of threats to New 
England cottontail habitat that have resulted in the destruction and 
modification of habitat and a concomitant curtailment in the species' 
range. Although implementation of the Conservation Strategy is 
underway, the population and habitat levels specified have not yet been 
attained (Fuller and Tur 2015, p. 18). Consequently, despite previous 
and ongoing conservation actions, we conclude that the destruction, 
modification, or curtailment of the New England cottontail's range 
continues to be a threat. In the Policy for the Evaluation of 
Conservation Efforts Analysis section below we further evaluate the 
Conservation Strategy to determine if the threat is expected to persist 
into the future.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

Recreational Hunting
    The New England cottontail is considered a small game animal by the 
northeastern States' wildlife agencies. It is legally hunted within 
season and with bag limitations in four of the six States known to have 
extant populations: New York, Connecticut, Massachusetts, and Rhode 
Island. Maine closed its cottontail season in 2004, and it remains 
closed (MEDIFW 2004, MEDIFW 2015). New Hampshire has modified its 
hunting regulations to prohibit the take of cottontails in those 
portions of the State where the New England cottontail is known to 
occur (NHFG 2004, NHFG 2015).
    One turn-of-the-century account relative to hunting New England 
cottontails (Fisher 1898, p. 198) states that ``although hundreds are 
killed every winter nevertheless they appear to be just as common at 
the present time as 20 years ago.'' Tracy (1995, p. 12) reported 
extensive hunting as a possible cause for the lack of cottontails at 
one Connecticut site, but provided no supporting data.
    Carlton et al. (2000, p. 46) suggest that overhunting of New 
England cottontails led to their decline in the mid-20th century, and 
that this decline indirectly contributed to the deleterious 
introduction of eastern cottontails by hunters seeking to compensate 
for the lost opportunity to hunt rabbits. The Service concurs that the 
introduction of eastern cottontails, a nonnative competitor, has been a 
factor in the decline of New England cottontail populations (see Factor 
C below) because eastern cottontails are now the predominant rabbit 
throughout all of the former range of the New England cottontail, 
except southern Maine. The prevailing view indicates the primary 
determinant of cottontail abundance is habitat (Chapman et al. 1982, p. 
114). Available evidence suggests that habitat loss through forest 
maturation and other causes (Jackson 1973, p. 21; Brooks and Birch 
1988, p. 85; Litvaitis et al. 1999, p. 101), rather than hunting 
pressure, was the primary reason for the decline of New England 
cottontail populations in the mid-20th century.
    Although hunting of New England cottontails occurs, hunting 
pressure is low relative to the overall abundance of eastern and New 
England cottontails and not a significant source of mortality compared 
to other factors. State wildlife biologists postulate that hunting has 
a minimal effect on the New England cottontail population in those 
States where hunting is legal (Parker, in litt. 2004; Stolgitis, in 
litt. 2000; Scarpitti and Piche, in litt. 2014; Tefft et al., in. litt. 
2014; Kilpatrick et al., in litt. 2014, Novak et al., in litt. 2014). 
Most States now have fewer rabbit and other small game hunters than in 
earlier decades (S. Cabrera, in litt. 2003; J. Organ, in litt. 2002; 
U.S. Department of the Interior and U.S. Department of Commerce 2002), 
and the New England cottontail is not the rabbit species harvested by 
most small game hunters. For example, in a 54-month study of eastern 
and New England cottontails in Connecticut, approximately 87 percent of 
the 375 rabbits killed by hunters and examined by the State were 
identified as eastern cottontails, and approximately 13 percent were 
New England cottontails (adapted from Goodie et al. 2005, p. 4 and 
Table 2). Similarly, in Rhode Island, most rabbit hunting occurs on 
farm lands, where the eastern cottontail is most often the targeted 
species and New England cottontails are absent (Stolgitis, in litt. 
2000; Tefft et al., in litt. 2014). In a New Hampshire study prior to 
the closing of cottontail hunting, of 50 collared New England 
cottontails

[[Page 55296]]

monitored, only 1 was taken by a hunter (J. Litvaitis, pers. comm., 
2000).
    In addition to level of hunter effort, the New England cottontail's 
behavior also influences its risk of exposure to hunting mortality. For 
example, New England cottontails forage within or close to dense cover 
(Smith and Litvaitis 2000, p. 2134), and typically hold in safe areas 
when disturbed. They also tend to remain in dense habitat and are, 
therefore, not as easily run by hounds and taken by hunters as eastern 
cottontails or snowshoe hares (Kilpatrick et al., in litt. 2014). 
Research shows that New England cottontails are more vulnerable to 
mortality from predation in smaller patches of habitat than in larger 
ones (Barbour and Litvaitis 1993, p. 321). This pattern may hold true 
for hunting mortality as well because rabbits on small patches 
eventually exploit food available in the best cover, and venture 
farther from shelter to feed where there is less escape cover in which 
to hide.
Pest Management
    Rabbits may be regarded as pests and killed by gardeners and 
farmers. However, because of differences in habitat preference of the 
two cottontail species, most farmers and homeowners are more likely to 
encounter eastern cottontails, which occur in the more open habitats of 
farms and residential lawns, than New England cottontails. Therefore, 
targeted pest management of rabbits is unlikely to be a significant 
source of mortality of New England cottontails.
    In summary, based on the best available information, we concur with 
Litvaitis' (1993a, p. 11) previous assessment that hunting restrictions 
or other nonhabitat-based management will likely have no influence on 
current or future populations of the species, and we conclude that 
current hunting pressure is a stressor for only a very limited number 
of individual New England cottontails and does not appear to be a 
significant mortality factor or threat for the species as a whole. 
While the best available information indicates the hunting is not a 
threat now or likely to be in the future, should the New England 
cottontail's population decline to substantially low levels in the 
future such that the viability of individual animals become 
substantially important to the species as a whole, the current stressor 
of hunting mortality may rise to the level of a threat. In addition, we 
have no information to indicate that pest management actions are 
affecting New England cottontails.
Conservation Efforts To Reduce Overutilization for Commercial, 
Recreational, Scientific, or Educational Purposes
    As discussed above, New Hampshire does not allow cottontail hunting 
in areas where the New England cottontail is known to occur, and Maine 
does not allow cottontail hunting at all. We are unaware of any other 
conservation efforts to eliminate the very limited hunting mortality 
occurring in the species' range. However, as discussed above, 
increasing habitat patch size (Factor A) may further reduce the limited 
exposure that individual New England cottontails have to hunting 
mortality.
    Summary of Factor B--We conclude based on the best scientific and 
commercial information available that overutilization for commercial, 
recreational, scientific, or educational purposes does not currently 
pose a threat to the New England cottontail, nor is it likely to become 
a threat in the future.

Factor C. Disease or Predation

Disease
    Cottontails are known to contract a number of different diseases, 
such as tularemia, and are naturally afflicted with both ectoparasites 
such as ticks, mites, and fleas and endoparasites such as tapeworms and 
nematodes (Eabry 1968, pp. 14-15). Disease has been attributed to 
population declines in rabbits over numerous areas (Nelson 1909, p. 
35); however, there is little evidence to suggest disease is currently 
a limiting factor for the New England cottontail. DeVos et al. (1956) 
in Eabry (1983, p. 15) stated that the introduced eastern cottontail on 
the Massachusetts islands of Nantucket and Martha's Vineyard probably 
competed with the native New England cottontail and introduced 
tularemia to the islands. However, it is not known whether tularemia 
played a role in the disappearance of New England cottontail from the 
islands. Chapman and Ceballos (1990, p. 96) do not identify disease as 
an important factor in the dynamics of contemporary cottontail 
populations. Rather, they indicate that habitat is key to cottontail 
abundance and that populations are regulated through mortality and 
dispersal (see the Life History and Factor A sections above for further 
discussion regarding the importance of habitat).
    Three efforts are currently underway involving research and 
monitoring of disease and parasites in the New England cottontail. 
First, wild New England cottontails obtained as breeding stock for the 
captive-breeding effort at the Roger Williams Park Zoo in Providence, 
Rhode Island, receive a complete veterinary exam (Fuller and Tur 2015, 
p. 50). Additionally, researchers at Brown University are studying the 
disease ecology of New England and eastern cottontails (Smith, in litt. 
2014). And lastly, in New York, researchers are studying parasites 
(Fuller and Tur 2015, p. 54). To date, no incidences of disease or 
parasites have been reported from these three monitoring efforts or 
from other sources. The best available information indicates that 
disease is not a threat to the New England cottontail.
Predation
    Brown and Litvaitis (1995, p. 1007) found that mammalian predators 
accounted for the loss of 17 of 40 New England cottontails in their 
study. Barbour and Litvaitis (1993, p. 325) determined that coyotes 
(Canis latrans) and red foxes were the primary predators of New England 
cottontails in New Hampshire. Coyotes first appeared in New Hampshire 
and Maine in the 1930s, in Vermont in the 1940s, and in southern New 
England in the 1950s (Foster et al. 2002, p. 1348; DeGraaf and Yamasaki 
2001, p. 341). Since then, coyote populations have increased throughout 
the Northeast (Foster et al. 2002, p. 1348; Litvaitis and Harrison 
1989, p. 1180), and they even occur on many offshore islands. Further, 
coyotes have become especially abundant in human-dominated habitats 
(Oehler and Litvaitis 1996, p. 2070). Litvaitis et al. (1984, p. 632) 
noted that cottontails were a major prey of bobcats (Felis rufus) in 
New Hampshire during the 1950s, and were recorded in the stomachs of 43 
percent of the bobcats examined; later, it was determined that the 
cottontails found in the bobcat study were most likely all New England 
cottontails (Litvaitis, in litt. 2005). In addition to coyotes and 
bobcats, other mammalian predators of cottontail rabbits in New England 
include weasels (Mustela sp.) and fishers (Martes pennanti). Avian 
predation is also considered a source of mortality for New England 
cottontails (Smith and Litvaitis 1999, p. 2136), and both barred owls 
(Strix varia) and great horned owls (Bubo virginianus) took cottontails 
in a New Hampshire study, where an enclosure prevented losses to 
mammalian predators. Litvaitis et al. (2008, p. 180) conclude that the 
abundance of hunting perches for red-tailed hawks (Buteo jamaicensis) 
and other raptors reduces the quality of

[[Page 55297]]

habitat afforded cottontails along power lines.
    Winter severity, measured by persistence of snow cover, is believed 
to affect New England cottontail survival because it increases the 
rabbits' vulnerability to predation, particularly in low-quality 
habitat patches (Brown and Litvaitis 1995, pp. 1005-1011). Compared to 
snowshoe hares, New England cottontails have proportionately heavier 
foot loading (i.e., feet sink farther into the snow) and do not turn 
white in winter (pelage color contrasts with snow making the species 
more visible to predators). Villafuerte et al. (1997, p. 151) found 
that snow cover reduces the availability of high-quality foods, and 
likely results in rabbits becoming weakened nutritionally. In a 
weakened state, rabbits are more vulnerable to predation. Brown and 
Litvaitis (1995, pp. 1005-1011) found that, during winters with 
prolonged snow cover, a greater proportion of the cottontails in their 
study were killed by predators. Eighty-five percent of the current 
occurrences of the New England cottontail are within 50 miles of the 
coast, and 100 percent are within 75 miles of the coast. Litvaitis and 
Johnson (2002, p. 21) hypothesize that snow cover may explain this 
largely coastal distribution of this species in the Northeast 
(generally less snow falls and fewer snow cover days occur in coastal 
versus interior areas) and may be an important factor defining the 
northern limit of its range. The preceding studies suggest that a 
stochastic event, such as a winter or consecutive winters with 
unusually persistent snowfall (see Factor E--Climate Change), will 
reduce the number and distribution of New England cottontails due to 
predation. This effect would not have been a concern under historical 
conditions. However, with the current level of habitat fragmentation 
and the number of small patches of habitat (Factor A), coupled with 
vulnerability to predation in these small patches, winter severity 
could affect the persistence of local populations and could contribute 
to further reductions in the range of the species.
    New England cottontails are known or expected to be killed by 
domestic dogs (Canis familiaris) and cats (Felis catus) (Walter et al. 
2001, p. 17; Litvaitis and Jakubas 2004, p. 15; Kays and DeWan 2004, p. 
4). The significance of the domestic cat as a predator on numerous 
species is well known (Coleman et al. 1997, pp. 1-8). The domestic cat 
has been identified as a significant predator of the endangered Lower 
Keys marsh rabbit (Sylvilagus palustris hefneri), and is considered the 
single biggest threat to the recovery of that species (Forys and 
Humphrey 1999, p. 251). According to the American Veterinary Medical 
Association (2002), cats occur in 31.6 percent of homes in the United 
States, and the average number of cats per household is 2.1. We do not 
have direct evidence regarding the role of domestic cats in influencing 
New England cottontail populations; however, Rhode Island biologists 
hypothesize that cats may be a threat to New England cottontails in 
that State (Tefft et. al., in litt. 2014). Given the high human 
population and housing densities found throughout the range of the New 
England cottontail, the domestic cat may be a predator of the species, 
though the lack of specific information makes it impossible to 
determine the extent of the possible predation.
    Predation is a natural source of mortality for all rabbits. Under 
historical circumstances predation would not have been a factor that 
posed a risk to the New England cottontail's survival. However, the 
majority of present-day thicket habitats supporting New England 
cottontails are of an insufficient size to provide adequate cover and 
food to sustain the species' populations amid high predation rates from 
today's more diverse set of natural and human-induced mid-sized 
carnivores (Brown and Litvaitis 1995, pp. 1005-1011; Villafuerte et al. 
1997, pp. 148-149).
    The best available information suggests that land use patterns 
influence predation rates and New England cottontail survival in 
several ways. Brown and Litvaitis (1995, pp. 1005-1011) compared the 
survival of transmitter-equipped New England cottontails with habitat 
features in surrounding habitat patches. They found that the extent of 
developed lands, coniferous cover, and lack of surface water features 
were associated with an increase in predation rates. In addition, 
Oehler and Litvaitis (1996, pp. 2070-2079) examined the effects of 
contemporary land uses on the abundance of coyotes and foxes and 
concluded that the abundance of these generalist predators doubled as 
forest cover decreased and agricultural land use increased. Thus, the 
populations of predators on the New England cottontail increased 
substantially at the times prior to the regeneration of agricultural 
and other lands to more mature forests, which further depressed New 
England cottontail populations.
    The abundance of food and risk of predation are highly influential 
in determining the persistence of small- and medium-sized vertebrates 
such as the New England cottontail. Barbour and Litvaitis (1993, pp. 
321-327) found that, as food in the most secure areas was depleted, New 
England cottontails were forced to utilize lower quality forage or feed 
farther from cover where the risk of predation was greater and that, as 
a result, New England cottontails on small patches of habitat were 
killed at twice the rates and earlier in winter than cottontails on 
larger habitat patches. Furthermore, Villafuerte et al.'s (1997, pp. 
149-150) study of New England cottontail urea nitrogen:creatinine 
ratios demonstrated that New England cottontails on small patches 
exhibited reduced ratios that were indicative of nutrient deprivation 
and that may have led individuals to forage in suboptimal cover where 
they experienced higher predation rates than individuals occupying 
larger patches (Villafuerte et al. 1997, pp. 149-150). Villafuerte et 
al. (1997, p. 151) concluded that forage limitations imposed by habitat 
fragmentation determine the viability of local populations of New 
England cottontails by influencing their vulnerability to predation.
    Thus, as landscapes become more fragmented, vulnerability of New 
England cottontails to predation increases not only because there are 
more predators, but also because cottontail habitat quantity and 
quality (forage and escape cover) are reduced (Smith and Litvaitis 
2000, pp. 2134-2140). Individuals on larger patches were less 
vulnerable to predation; therefore, large patches of habitat may be 
essential for sustaining populations of this species in a human-altered 
landscape.
Conservation Efforts To Reduce Disease or Predation
    As discussed above, disease is not known to be a threat to the New 
England cottontail. Therefore, no conservation measures to manage 
disease have been planned or implemented (Fuller and Tur 2012, p. 55). 
Nevertheless, as described above, three conservation efforts are 
underway to monitor and investigate new instances of disease should 
they occur within the species.
    Predation is considered to be a stressor, in that small New England 
cottontail populations occupying landscapes containing insufficient 
amounts of high-quality habitat are particularly vulnerable. Currently, 
there are no efforts in place to suppress predator numbers to increase 
New England cottontail survival (Fuller and Tur 2012, p. 65; Boland et 
al., in litt. 2014; Holman et al., in litt. 2014; Scarpitti and Piche, 
in litt. 2014; Tefft et

[[Page 55298]]

al., in litt. 2014; Kilpatrick et al., in litt. 2014; Novak et al., in 
litt. 2014). Instead, conservation efforts to increase habitat 
availability, as described in the Conservation Actions to Reduce 
Habitat Destruction, Modification, or Curtailment of Its Range section 
above, are being implemented that indirectly reduce New England 
cottontail vulnerability to predation.
    Summary of Factor C--Disease does not appear to be an important 
factor affecting New England cottontail populations and is not 
considered a threat to the species, nor is it expected to become a 
threat in the future. Predation is a routine aspect of the life history 
of most species, and under natural conditions (i.e., prior to 
settlement by Europeans in the Northeast and the substantial habitat 
alteration that has followed) predation was likely not a threat to the 
persistence of the New England cottontail. Today, however, the 
diversity of predators has increased, the amount of suitable cottontail 
habitat has decreased, and the remaining habitat is highly fragmented 
with remnant habitat patches often small in size. The best available 
information strongly suggests that most cottontails occupying small 
habitat patches will be killed by predators, as few rabbits that 
disperse into or are born in those areas live long enough to breed; 
thus, most small thicket habitat patches are unoccupied by cottontails. 
Since predation is strongly influenced by habitat quantity and quality, 
we conclude that the primary threat to the species is the present 
destruction, modification, and curtailment of its habitat and range 
(Factor A), and that predation is a contributing threat to the New 
England cottontail's viability. In the Policy for the Evaluation of 
Conservation Efforts Analysis section below we further evaluate the 
Conservation Strategy to determine if the threat of predation is 
expected to persist into the future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    There are only limited regulatory mechanisms available to address 
the destruction or modification of New England cottontail habitat, 
especially on private lands. Local governments regulate development 
through zoning ordinances; we are unaware of any locally developed 
regulatory mechanisms that specifically address threats to New England 
cottontail habitat. Some New England cottontail occurrences are 
associated with sites that contain or are adjacent to riparian 
vegetation, such as borders of lakes, beaver wetlands, and rivers. 
However, the New England cottontail is primarily an upland, terrestrial 
species that sometimes occurs along the margins of these wetland types. 
Federal and State laws, such as section 404 of the Clean Water Act of 
1972 (86 Stat. 816) and Maine's Natural Resources Protection Act (Title 
38, section 435-449), that provide protection to wetlands and upland 
buffers offer protection to only a small number of New England 
cottontail occurrences.
    State wildlife agencies in the Northeast have the authority to 
regulate hunting of the New England cottontail by setting hunting 
seasons and bag limits. However, most northeastern States cannot 
restrict the take of New England cottontails without also reducing 
hunting opportunities for the eastern cottontail, a common species, 
because the two species are similar in appearance and cannot be easily 
distinguished at a distance, and sometimes occur within the same 
habitat patches (Walter et al. 2001, p. 21). In Maine, where the only 
cottontail species is the New England cottontail, cottontail hunting 
has been prohibited since 2004 (MEDIFW 2004; MEDIFW 2014). In 
recognition of the declining status of the New England cottontail, New 
Hampshire similarly closed the eastern cottontail hunting season in 
2004/2005 in those portions of the State where New England cottontails 
are known to occur, and it has remained closed (NHFG 2004; NHFG 2014). 
Harvest of New England cottontail is legal in Massachusetts, Rhode 
Island, Connecticut, and New York (see discussion under Factor B). 
Under Factor B, above, we concluded that hunting, by itself, is not a 
threat to the New England cottontail at the species level, but may be a 
concern for small localized populations where hunting mortality may 
contribute to further declines in those areas.
    The New England cottontail is currently listed under State 
endangered species laws in Maine and New Hampshire (Boland et al., in 
litt. 2014; Holman et al., in litt. 2014). No other State currently 
lists the New England cottontail as a threatened or endangered species. 
The Endangered Species Conservation Act (ESCA) of New Hampshire 
prohibits the export, take, and possession of State species that have 
been identified as endangered or threatened (Revised Statutes Annotated 
[RSA] 212-A:7). However, the executive director of NHFGD may permit 
certain activities, including those that enhance the survival of the 
species. Penalties for violations of RSA 212-A:7 of the ESCA are 
identified (RSA 212-A:10, II). The Maine Endangered Species Act (MESA) 
prohibits the export, take, and possession of State species that have 
been identified as endangered or threatened (12 MRS sections 12801-
12810). Under MESA's endangered designation, the State agencies have 
the ability to review projects that are carried out or funded by State 
and Federal agencies and assess those projects for effects to the New 
England cottontail. In some cases, projects may be modified or 
mitigated to ensure that deleterious effects to the New England 
cottontail are minimized. However, the existing statutes cannot require 
the creation and maintenance of suitable habitat at the spatial scales 
described under Factor A; consequently, the loss of habitat due to 
natural forest succession is likely to proceed.
    Since the State listing of the species, the distribution of the New 
England cottontail has continued to decline in Maine (Fenderson 2010, 
p. 104), while in New Hampshire the distribution declined, but is now 
improving at some locations where active management is occurring 
(Fenderson 2014, p. 12; H. Holman, pers. comm., 2015). This slight 
improvement, however, is likely attributed to implementation of 
voluntary conservation measures to improve habitat and population 
augmentation efforts described under Factor A (H. Holman, pers. comm., 
2015), and not to regulatory processes. The New England cottontail has 
been identified as a ``Species of Greatest Conservation Concern'' 
(SGCN) in all seven State Comprehensive Conservation Strategies 
throughout the species' historical and current range. Species of 
Greatest Conservation Concern are defined as species that are rare or 
imperiled or whose status is unknown. As a result, the New England 
cottontail is receiving additional attention by State managers. For 
example, New Hampshire suggests development of early successional 
habitat networks in landscapes currently occupied by the species 
(http://www.wildlife.state.nh.us/Wildlife/wildlife_plan.htm (accessed 
March 2015)). However, the identification of the New England cottontail 
as an SGCN is intended to convey concern so as to draw conservation 
attention to the species and provides no regulatory function.
Conservation Efforts To Increase Adequacy of Existing Regulations
    While there are conservation efforts to raise awareness of the 
species' habitat needs, these are not regulatory in nature. We are 
unaware of any ongoing conservation efforts to increase the

[[Page 55299]]

adequacy of existing regulatory mechanisms.
    Summary of Factor D--We conclude that the best available 
information indicates hunting is not a limiting factor for the species 
and the existing regulatory mechanism to control the legal take of New 
England cottontails through hunting is adequate. Conversely, we are 
unaware of any locally developed regulatory mechanisms, such as local 
zoning ordinances, specifically designed to address the threat of 
habitat destruction, modification, or curtailment for this species. 
While we cannot consider non-regulatory mechanisms here under Factor D, 
we acknowledge in Factor A above and the Policy for the Evaluation of 
Conservation Efforts section below that the threat of habitat 
destruction, modification, or curtailment is being managed now and is 
likely to continue to be managed into the future.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Competition
    The eastern cottontail was released into much of the range of the 
New England cottontail, and the introduction and spread of eastern 
cottontails have been a factor in reducing the range and distribution 
of the New England cottontail. Prior to their introduction, the eastern 
cottontail extended northeast only as far as the lower Hudson Valley 
(Bangs 1894, p. 412). By 1899, tens of thousands of individuals of four 
or five different subspecies of the eastern cottontail were introduced 
to the New England cottontail's range, beginning on Nantucket Island, 
Massachusetts (Johnston 1972, p. 3). By the 1930s, eastern cottontails 
were known to occur in western Connecticut (Goodwin 1932, p. 38), most 
likely as a result of introductions (Hosley 1942, p 18). Large-scale 
introductions of eastern cottontails to New Hampshire (Silver 1957, p. 
320), Rhode Island (Johnston 1972, p. 6), Massachusetts (Johnston 1972, 
pp. 4-5), and possibly Vermont (Kilpatrick, in litt. 2002) have firmly 
established the eastern cottontail throughout most of New England where 
it remains common. The exception is Maine, where the New England 
cottontail remains the only Sylvilagus species (Litvaitis et al. 2006, 
p. 1193; Boland et al., in litt. 2014; Kilpatrick et al., in litt. 
2014; Tefft et al., in litt. 2014; Novak et al., in litt. 2014).
    The eastern cottontail is larger (1,300 gm (2.9 lb)) than the New 
England cottontail (Chapman and Ceballos 1990, p. 96). Probert and 
Litvaitis (1996, p. 289) found that eastern cottontails, though larger, 
were not physically dominant over New England cottontails and concluded 
that interference competition did not explain the change in the 
distribution and abundance of the latter. In a follow-up investigation, 
Smith and Litvaitis (2000, entire) assessed winter foraging strategies 
used by the two species by monitoring the response of eastern and New 
England cottontails to variations in food and cover within large 
enclosures. Smith and Litvaitis (2000, p. 239) found that the eastern 
cottontail was able to maintain physical condition when food resources 
in cover were low by venturing into open areas to feed from feeders 
supplied with commercially available rabbit forage. In contrast, New 
England cottontails were reluctant to venture into open areas to 
exploit these resources, and their physical condition declined (Smith 
and Litvaitis 2000, p. 2138). Smith and Litvaitis (2000, pp. 2138-2139) 
also found that when New England cottontails did venture into open 
areas for forage, they experienced higher rates of predation by owls 
than did eastern cottontails.
    Smith and Litvaitis (2000, p. 2139) suggest that the increased 
survival of eastern cottontails foraging in low cover areas is made 
possible by their enhanced predator detection ability. In a companion 
study, Smith and Litvaitis (1999, p. 57) reported that the eastern 
cottontail had a larger exposed surface area of the eye and 
consequently had a greater reaction distance to a simulated owl than 
did New England cottontails. Consequently, eastern cottontails have the 
ability to use a wider range of habitats, including relatively open 
areas such as meadows and residential back yards, compared to the New 
England cottontail, and may be able to exploit newly created habitats 
sooner than New England cottontails (Litvaitis et al. 2008).
    In addition to the morphological and behavioral differences between 
the two species, there are important physiological differences that may 
influence competition between the two species. Tracy (1995, pp. 65-67) 
compared the metabolic physiology of the two species and found that the 
eastern cottontail had a significantly higher basal metabolism (the 
amount of energy expended while at rest). Based on the findings, Tracy 
(1995, pp. 68-75) suggested that the difference in metabolic rate may 
confer a competitive advantage on eastern cottontails, by affording 
eastern cottontails an increased reproductive capacity and predator 
avoidance capability, and to displace the New England cottontail from 
areas containing high quality food resources. Conversely, eastern 
cottontails may be unable to meet their metabolic demands in habitats 
characterized by relatively nutrient poor food resources such as 
ericaceous (related to the heath family) forests, whereas the New 
England cottontail may be able to persist. The ability to maintain 
winter body condition while occupying small habitat patches may be the 
reason the eastern cottontail is more fecund (capable of producing 
offspring) than the New England cottontail (Chapman and Ceballos 1990, 
p. 96) and the reason eastern cottontails, once established, are not 
readily displaced by New England cottontails (Probert and Litvaitis 
1996, p. 292).
    The competitive advantage of eastern cottontails, however, may be 
lost in nutrient-deficient sites, such as in pine barrens and 
ericaceous shrublands, where resources to meet the higher energy 
demands of this species are lacking but may be adequate to support the 
resource needs of the New England cottontail (Tracy 1995, p. 69). These 
nutrient-deficient sites are relatively stable and persistent through 
time in comparison to other disturbance-generated habitats, such as 
young forests. Litvaitis et al. (2008, p 176) suggested that relatively 
stable shrublands may allow New England cottontails to coexist with 
eastern cottontails. This ability to persist in stable habitats may 
explain why habitats occupied by the New England cottontail in 
Connecticut are characterized by greater canopy cover and basal area 
than sites occupied by eastern cottontails (Gottfried 2013, p. 18).
    Throughout most of the New England cottontail's range, 
conservationists consider the presence of eastern cottontails among the 
most substantial conservation issues to be addressed if efforts to 
restore the New England cottontail are to be successful (Probert and 
Litvaitis 1996, p. 294; Fuller and Tur 2012, p. 20; Scarpitti and 
Piche, in litt. 2014; Tefft et al., in litt. 2014; Kilpatrick et al., 
in litt. 2014; Novak et al., in litt. 2014). Uncertainty remains, 
however, regarding the best approaches to managing New England and 
eastern cottontail populations to ensure that the former persists 
(Fuller and Tur 2012, pp. 20-21). The best available information 
strongly suggests that competition with eastern cottontails has been a 
factor in the decline of the New England cottontail and that the effect 
is greatest in landscapes comprising small habitat patches. Therefore, 
we conclude that the primary threat to the species is the present 
destruction, modification, and curtailment of its habitat and range

[[Page 55300]]

(Factor A), and that competition with eastern cottontails is a 
contributing threat to the New England cottontail's viability.
White-Tailed Deer Herbivory
    In our previous CNORs (71 FR 53756; 72 FR 69034), we concluded that 
competition with, and habitat degradation by, white-tailed deer 
(Odocoileus virginianus) may be a risk factor to the New England 
cottontail as a result of the deer's effect on forest regeneration. 
This earlier conclusion was based on the white-tailed deer's high 
population densities (J. McDonald, in litt. 2005), their similar food 
habits to cottontails (Martin et al. 1951, pp. 241-242, 268-270), and 
their documented negative direct and indirect effects on forest 
vegetation in many areas of the eastern United States (Latham et al. 
2005, pp. 66-69, 104; deCalesta 1994, pp. 711-718). While it was 
reasonable to conclude at the time that white-tailed deer may be 
competing with New England cottontail for food because the two species 
overlapped in areas of occurrence and it was the best available 
information, we had no direct evidence that deer herbivory was having 
an actual effect on New England cottontail. Since then, we requested 
specific information from State wildlife agencies indicating that the 
presence of deer is affecting the status of the New England cottontail. 
The State wildlife agencies responded that they had no information 
indicating deer herbivory was affecting New England cottontail (Boland 
et al., in litt. 2014; Holman et al., in litt. 2014; Scarpitti and 
Piche, in litt. 2014; Tefft et al., in litt. 2014; Kilpatrick et al., 
in litt. 2014; Novak et al., in litt. 2014). Furthermore, we have no 
such information from any other source that this one-time potential 
risk factor is presently having negative effects on New England 
cottontail. Consequently, lacking direct evidence that herbivory by 
white-tailed deer is currently compromising habitat quality and 
quantity for the New England cottontail, we conclude that excessive 
herbivory by white-tailed deer is currently not a threat to the 
species.
Road Mortality
    State wildlife agencies report that road kills are an important 
source for obtaining specimens of rabbits, including the New England 
cottontail. Road-killed rabbits were second only to hunting mortality 
as a source for cottontail specimens for a distributional study in 
Connecticut: Of 108 cottontail specimens obtained, 3 were identified as 
New England cottontails (Walter et al. 2001, pp. 13-19). Although road 
mortality does result in the death of a few individuals, New England 
cottontail populations are not considered to be significantly affected 
by vehicular mortality (Boland et al., in litt. 2014; Holman et al., in 
litt. 2014; Scarpitti and Piche, in litt. 2014; Tefft et al., in. litt. 
2014; Kilpatrick et al., in litt. 2014; Novak et al., in litt. 2014).
Small Population Size
    As provided in the Life History section, extant populations of New 
England cottontails are believed to function as metapopulations with 
local extinction events likely the result of demographic, 
environmental, and genetic stochasticity. Existing populations in Maine 
likely contain fewer than 700 individuals scattered across four 
separate areas (Boland et al., in litt. 2014). Similarly, in New 
Hampshire the current population is thought to contain fewer than 200 
individuals located within two distinct areas (Holman et al., in litt. 
2014). As a consequence of habitat fragmentation and loss, these 
populations exhibit the effects of small population size, as evidenced 
by the presence of genetic drift (change in the frequency of alleles 
(gene variants) in a population due to random sampling of individuals) 
and critically low effective population sizes (number of individuals 
who contribute offspring to the next generation) (Fenderson et al. 
2014, entire). For these populations, Fenderson et al. (2014, p. 17) 
suggested that habitat creation alone may be insufficient to improve 
their status and that translocations may be necessary to augment 
existing populations. The effect of small population size is likely 
exhibited in Rhode Island's remaining population, since current 
estimates indicate that there are fewer than 100 individuals within the 
State (Tefft et al., in litt. 2014). In the remainder of the New 
England cottontail's range, populations are generally larger and 
presumed to be less affected by fragmentation (Scarpitti and Piche, in 
litt. 2014; Kilpatrick et al., in litt. 2014; Novak et al., in litt. 
2014); consequently, the effects of small population size are not 
anticipated to be a significant biological consequence throughout the 
species' range. However, if the total number of New England cottontail 
populations continues to decline, the remaining populations may 
experience the deleterious effects of small population size.
Climate Change
    Our analyses under the Act include consideration of observed or 
likely environmental effects related to ongoing and projected changes 
in climate. As defined by the Intergovernmental Panel on Climate Change 
(IPCC), ``climate'' refers to average weather, typically measured in 
terms of the mean and variability of temperature, precipitation, or 
other relevant properties over time, and ``climate change'' thus refers 
to a change in such a measure that persists for an extended period, 
typically decades or longer, due to natural conditions (e.g., solar 
cycles) or human-caused changes in the composition of the atmosphere or 
in land use (IPCC 2013, p. 1450). Detailed explanations of global 
climate change and examples of various observed and projected changes 
and associated effects and risks at the global level are provided in 
reports issued by the IPCC (2014 and citations therein); information 
for the United States at national and regional levels is summarized in 
the National Climate Assessment (Melillo et al. 2014 entire and 
citations therein; see Melillo et al. 2014, pp. 28-45 for an overview). 
Because observed and projected changes in climate at regional and local 
levels vary from global average conditions, rather than using global-
scale projections we use ``downscaled'' projections when they are 
available and have been developed through appropriate scientific 
procedures, because such projections provide higher resolution 
information that is more relevant to spatial scales used for analyses 
of a given species and the conditions influencing it (see Melillo et 
al. 2014, Appendix 3, pp. 760-763 for a discussion of climate modeling, 
including downscaling). In our analysis, we use our expert judgment to 
weigh the best scientific and commercial information available in our 
consideration of relevant aspects of climate change and related 
effects.
    Downscaled climate change models for the Northeastern United States 
(Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, 
Connecticut, New York, New Jersey, and Pennsylvania) indicate that 
temperatures will increase in the future, more so in summer than in 
winter (Hayhoe et al. 2008, p. 433). Overall, the region is expected to 
become drier overall, but average seasonal precipitation is expected to 
shift toward winter increases of 20 to 30 percent with slightly drier 
summers (Hayhoe et al. 2008, p. 433). Variations across the region are 
also expected, with northern portions of the region drying out more 
than southern areas, with a ``hot spot'' developing over coastal 
southern Maine (Hayhoe et al. 2008, p. 433). Although the New England 
cottontail is a habitat specialist that is reliant upon dense

[[Page 55301]]

shrublands (see Life History section), sites occupied by the species 
are variable and range from droughty (e.g., pitch pine-scrub oak) to 
wet (e.g., shrub wetlands). Given the range of habitats occupied by the 
species, predicting the effects of climate change is complicated.
    Climate change is anticipated to alter the frequency, intensity, 
duration, and timing of forest disturbance (Dale et al. 2001, entire), 
which is likely to positively influence habitat for the species. 
Climate change is also expected to affect invasive species 
disproportionately to native species (Hellmann et al. 2008, entire), 
which is likely to influence the distribution and abundance of the 
eastern cottontail, as well as those habitats comprising exotic 
invasive shrubs (e.g., Rosa multiflora and Lonicera spp.), and, 
therefore, may affect the New England cottontail. Consequently, 
accurately predicting climate change effects to the New England 
cottontail is not easily disentangled. That said, the bioclimatic 
envelope (species distribution as predicted by climate) for the New 
England cottontail is predicted to increase by 110 percent by the end 
of the century and shift approximately 1 degree poleward (Leach et al. 
2014, p. 126), which suggests that the species' distribution may 
increase with climate change.
Conservation Efforts To Reduce Other Natural or Manmade Factors 
Affecting Its Continued Existence
Competition
    As previously described under Conservation Actions to Reduce 
Habitat Destruction, Modification, or Curtailment of Its Range, there 
are many previous and ongoing conservation efforts to increase and 
maintain suitable habitat. Increased habitat patch size and 
connectivity will reduce the effects of eastern cottontail competition. 
However, there remain uncertainties regarding the best approaches to 
managing sympatric populations; therefore, research and monitoring has 
been identified as a top-priority need to address the conservation 
needs of the New England cottontail (Fuller and Tur 2012, pp. 20, 53, 
77-80, 114-120). For example, a study to determine the efficacy and 
benefits of managing eastern cottontails for the benefit of the New 
England cottontail is underway, and the results will be integrated into 
the Conservation Strategy's adaptive management process so that it may 
inform future management actions (Tur and Eaton, in litt. 2013; Fuller 
and Tur 2012, p. 114) (see the Policy for the Evaluation of 
Conservation Efforts Analysis section below for additional 
information).
Small Population Size
    To address the threat of small population size, the Conservation 
Strategy identifies the need for specific population management 
objectives, including captive breeding and relocation of New England 
cottontails (Fuller and Tur 2012, p. 61-67), which is further 
corroborated by Fenderson et al. (2014, entire) for populations in New 
Hampshire and Maine. A captive-breeding pilot program has been 
initiated at the Roger Williams Park Zoo (RWPZ) to evaluate and refine 
husbandry, captive propagation, and reintroduction protocols for the 
New England cottontail. A Technical Committee Captive-breeding Working 
Group facilitates and monitors implementation of this conservation 
tool. Since 2011, approximately 131 young have been produced at the 
RWPZ, and individually marked New England cottontails are released at 
sites in Rhode Island and New Hampshire (Fuller and Tur 2015, pp. 49-
53). Success of these efforts is indicated by the presence of unmarked 
animals, which suggests that released animals are successfully breeding 
(Fuller and Tur 2015, pp. 51-52).
    Through these efforts, populations of New England cottontails may 
be increasing and less susceptible to demographic and environmental 
stochastic events. Since these introductions involve the descendants 
from numerous geographic areas (Perrotti, in litt. 2014), we anticipate 
that genetic drift has been ameliorated and the possibility of genetic 
stochasticity affecting remnant populations in Rhode Island and New 
Hampshire has been reduced or eliminated. Nevertheless, genetic 
monitoring to determine the genetic health of these populations will be 
conducted (Fuller and Tur 2012, p. 54) (see the Policy for the 
Evaluation of Conservation Efforts Analysis section below). In 
contrast, plans to implement population augmentation in Maine may not 
occur until 2030 (Boland et al., in litt. 2014). Given the critically 
low effective population sizes in Maine, however, habitat creation 
alone may be insufficient (Fenderson et al. 2014, p. 17).
    Summary of Factor E--In summary, habitat modification resulting 
from high densities of white-tailed deer was once thought to be a 
threat to the New England cottontail, but is no longer a concern. The 
best available information indicates that climate change and road 
mortality are not threats: In fact, climate change may benefit the 
species. Eastern cottontails compete with New England cottontails for 
food and space and may be suppressing New England cottontail 
populations. Since the effects of small population size and competition 
with eastern cottontails are inextricably linked to habitat quality, 
quantity, and connectivity, we conclude that the primary threat to the 
species throughout most of its range is the present destruction, 
modification, and curtailment of its habitat and range (Factor A), and 
that small population size is a contributing threat to the New England 
cottontail's viability. In the Policy for the Evaluation of 
Conservation Efforts Analysis section below we further evaluate the 
Conservation Strategy to determine if the threat of small population 
size and eastern cottontails is expected to persist into the future, as 
required by section 4(b)(1)(A) of the Act.

Cumulative Effects From Factors A Through E

    As discussed above, habitat loss (Factor A) is the most significant 
threat to the New England cottontail. This directly affects the species 
through insufficient resources to feed, breed, and shelter and 
indirectly affects the species by amplifying the effects of predation 
(Factor C), competition with eastern cottontails (Factor E), and small 
population size (Factor E). In our analysis of these threats, we 
discussed previous and ongoing conservation efforts addressing these 
rangewide threats, which will be further analyzed in the Policy for the 
Evaluation of Conservation Efforts Analysis section below.
Policy for Evaluation of Conservation Efforts Analysis
    As presented in the Summary of Information Pertaining to the Five 
Factors above, section 4(b)(1)(A) of the Act and our regulations at 50 
CFR 424.119(f) require us to consider efforts by any State, foreign 
nation, or political subdivision of a State or foreign nation to 
protect the species. Such efforts would include measures by Native 
American Tribes and organizations. Also, Federal, Tribal, State, and 
foreign recovery actions (16 U.S.C. 1533(f)) and Federal consultation 
requirements (16 U.S.C. 1536) constitute conservation measures.
    In addition to identifying such efforts under the Act and our 
policy implementing this provision, known as the Policy for Evaluation 
of Conservation Efforts (PECE) (68 FR 15100; March 28, 2003), we must, 
at the time of the listing determination,

[[Page 55302]]

evaluate whether formalized conservation efforts provide sufficient 
certainty of effectiveness on the basis of whether the effort or plan 
establishes specific conservation objectives; identifies the necessary 
steps to reduce threats or factors for decline; includes quantifiable 
performance measures for the monitoring of compliance and 
effectiveness; incorporates the principles of adaptive management; and 
is likely to improve the species' viability by eliminating or 
adequately reducing one or more of the threats identified in our 
section 4(a)(1) analysis. We must also evaluate the conservation 
efforts to determine the certainty that they will be implemented on the 
basis of the availability of resources necessary to carry out the 
effort; the authority of the parties to carry out the identified 
actions; the regulatory and procedural requirements necessary to carry 
out the action are in place; the schedule for completing and evaluating 
the efforts; and the extent of voluntary participation necessary to 
achieve the conservation goals has been identified and will be secured. 
The criteria for PECE are not considered comprehensive evaluation 
criteria for evaluating certainty of the formalized conservation 
effort, and consideration of species, habitat, location, and effort is 
provided when it is appropriate. To satisfy the requirements of PECE, 
conservation plans should, at a minimum, report data on existing 
populations, describe activities taken toward conservation of the 
species, demonstrate either through data collection or best available 
science how these measures will alleviate threats, provide a mechanism 
to integrate new information (adaptive management), and provide 
information regarding certainty of implementation.
    An integral part of determining whether a species meets the 
definition of threatened or endangered requires us to analyze a 
species' risk of extinction. Central to this risk analysis is an 
assessment of the status of the species (i.e., is it in decline or at 
risk of decline, and what is the rate of decline or risk of decline) 
and consideration of the likelihood that current or future conditions 
or actions will promote or threaten a species' persistence. This 
determination requires us to make a prediction about the future 
persistence of a species, including consideration of both future 
negative and positive effects of anticipated human actions. For 
formalized conservation efforts that are not fully implemented, or 
where the results have not been demonstrated, we will consider PECE 
criteria in our evaluation of whether, and to what extent, the 
formalized conservation efforts affect the species' status under the 
Act. The results of our analysis may allow us to conclude that the 
threats identified in the section 4(a)(1) analysis have been 
sufficiently reduced or eliminated to such an extent that the species 
does not meet the definition of threatened or endangered, or is 
threatened rather than endangered.
    An agreement or plan intended to improve a species' status may 
contain numerous conservation objectives, not all of which are 
sufficiently certain to be implemented and effective. Those 
conservation efforts that are not sufficiently certain to be 
implemented and effective cannot contribute to a determination that 
listing is unnecessary, or a determination to list as threatened rather 
than endangered. Further, it is important to note that a conservation 
plan is not required to have absolute certainty of implementation and 
effectiveness to contribute to a listing determination. Rather, we need 
to be certain that the conservation objectives identified within the 
plan will be implemented and effective, such that the threats to the 
species are expected to be sufficiently reduced or eliminated. 
Regardless of the adoption of a conservation agreement or plan, if the 
best scientific and commercial information indicates that the species 
meets the definition of endangered or threatened on the day of the 
listing decision, then we must proceed with appropriate rulemaking 
under section 4 of the Act.
    Because the certainty of implementation and effectiveness of 
formalized conservation efforts may vary, PECE specifies that each 
effort will be evaluated individually (68 FR 15114). In the Rangewide 
Conservation Efforts section above, we introduced the development of a 
conservation planning effort beginning in 2008, which was later 
formalized in 2011 and resulted in the development of the Conservation 
Strategy (Fuller and Tur 2012, entire). This Conservation Strategy 
represents the Parties' planning process and guides actions intended to 
improve and maintain populations of New England cottontails throughout 
the species' current range. There are a number of other formalized 
actions interrelated to the Conservation Strategy, some of which 
precede its completion but were integral to its development and 
implementation. Since these interrelated formalized actions contribute 
to the overall Conservation Strategy and its goal of addressing the New 
England cottontail's primary threat--loss of habitat--we conclude that 
they can be batched as a single conservation effort, and that we are 
not required to analyze each agreement separately; rather, we briefly 
describe in our full PECE analysis (available at http://www.regulations.gov) those actions, such as the two Candidate 
Conservation Agreements with Assurances for Maine and New Hampshire, as 
contributing to the collective effort.
    Using the criteria in PECE, we evaluated the degree of certainty to 
which the Conservation Strategy would be effective at minimizing or 
eliminating threats to the New England cottontail. Our evaluation was 
facilitated by a recent report, entitled New England Cottontail 
Conservation Progress, 2014 Annual Performance Report (Fuller and Tur 
2015, entire, available at www.newenglandcottontail.org), hereafter 
referred to as the Performance Report. In addition to our review of 
performance, we assessed the status of the New England cottontail, the 
specific threats to New England cottontail populations, and 
conservation actions planned and implemented to address those threats, 
at the local or Focus Area-specific scale. This information was 
provided in individual Focus Area Status Screening Templates (FASSTs) 
that were prepared for most of the Focus Areas identified in the 
Conservation Strategy (Fuller and Tur 2012, pp. 90-113). We used this 
information to determine if the conservation actions planned within the 
Focus Areas would maintain or increase populations to the extent that 
they might contribute to the goals of the Conservation Strategy. 
Further, in October 2014, we convened a meeting of the Parties, with 
facilitation support provided by WMI, to assess the Parties' commitment 
to implementing the Conservation Strategy and its individual 
components.
PECE Analysis Summary
    Using the criteria in PECE, we evaluated the certainty of 
implementation and effectiveness of the Conservation Strategy. We have 
determined that the conservation objectives described therein have a 
high certainty of being implemented, based on the Parties' previous 
actions and commitments (Fuller and Tur 2015, entire) and the recent 
reaffirmation to its continuation (Sparks et al., in litt. 2014; 
Riexinger et al., in litt. 2014; Hyatt et al., in litt. 2014; Connolly, 
in litt. 2014; MacCallum, in litt. 2014; Ellingwood and Kanter, in 
litt. 2014; Weber, pers. comm. 2014; Weller, pers. comm. 2014). We have 
determined that the Conservation Strategy provides a high degree of 
certainty that it will be

[[Page 55303]]

effective. This is supported, in part, by the identification of all 
known threats, the development of actions to ameliorate them, 
monitoring, and application of the principles of adaptive management. 
Specifically, we find that the Conservation Strategy presents an 
effective approach that establishes a network of habitats of sufficient 
quality and quantity that is likely to compensate for the destruction, 
modification, and curtailment of the New England cottontail's habitat 
and range, the primary threat to the species. For example, the 
Conservation Strategy identifies 3,310 ha (8,179 ac) for land 
management activities to create, restore, or maintain suitable habitat; 
these management activities have been planned, initiated or completed 
and the initiated or completed projects have demonstrated examples of 
populations that have increased within specific patches (Fuller and Tur 
2015, entire). Based on our evaluation of the conservation effort 
described in the Conservation Strategy and associated documents, we 
find that the conservation effort provides a high degree of certainty 
of implementation and effectiveness.
    Our full analysis of the New England cottontail conservation effort 
pursuant to PECE can be found at http://www.regulations.gov.

Finding

    As required by the Act, we considered the five factors in assessing 
whether the New England cottontail is endangered or threatened 
throughout all of its range. We examined the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by the New England cottontail. We reviewed the 
petition, information available in our files, and other available 
published and unpublished information, and we consulted with recognized 
species and habitat experts and other Federal, State, and Tribal 
agencies. Based on our evaluation of the threats to the New England 
cottontail, we find that the present or threatened destruction, 
modification, or curtailment of its habitat or range (Factor A) is the 
most significant threat to the species. This directly affects the 
species through insufficient resources to feed, breed, and shelter and 
indirectly affects the species by amplifying the effects of predation 
(Factor C), competition with eastern cottontails (Factor E), and small 
population size (Factor E). Without the ongoing and planned 
implementation of the conservation measures described in the 
Conservation Strategy, these identified threats would remain at a level 
that would warrant listing of the New England cottontail.
    Thus, we next considered conservation efforts pursuant to section 
4(b)(1)(A) of the Act and our regulations at 50 CFR 424.119(f). This 
consideration includes an evaluation under the PECE policy of those 
conservation efforts within the Conservation Strategy, including 
commitments of funding and other resources, that have been implemented 
and not yet shown to be effective and those actions proposed for the 
future (see the Policy for the Evaluation of Conservation Efforts 
Analysis section above). Based on our evaluation of the conservation 
effort, as described in the Conservation Strategy and associated 
documents, we find that sufficient certainty of implementation and 
effectiveness is provided and the conservation effort forms part of the 
basis for our final listing decision for the New England cottontail. We 
find those actions taken under the auspices of the Conservation 
Strategy have yet to completely remove the threats specified above, but 
have been successful, and are anticipated to be fully successful in the 
future, in ameliorating the threats. For example, as of January 2015, 
the NRCS created or maintained approximately 3,700 ac (1,497 ha) of New 
England cottontail habitat under the Working Lands for Wildlife program 
(Fuller and Tur 2015, p. 59), and the agency anticipates implementing 
management actions on additional habitat as part of NRCS' 5-year plan. 
In addition, the 2,107 ac (852 ha) of scrub oak shrublands found on the 
Camp Edwards Training Site owned by the MDFW and leased to the 
Massachusetts Army National Guard are considered a stronghold for the 
New England cottontail, and conservation efforts to maintain and expand 
habitats are ongoing primarily through the use of prescribed fire 
(McCumber, in litt. 2015). Therefore, we conclude that the conservation 
efforts have reduced or eliminated current and future threats to the 
New England cottontail to the point that the species no longer is in 
danger of extinction now or in the foreseeable future.
    Additionally, although the current rangewide estimate suggests 
there are approximately 17,000 New England cottontails, we estimate 
that only 10,500 individuals currently occupy landscapes where 
persistence of the species is anticipated. This estimate falls short of 
the population goal of 13,500 individuals. Nevertheless, the 
conservation actions implemented have demonstrably improved the 
population status of the New England cottontail at some locations, and 
that improvement is expected to continue through the Conservation 
Strategy's 2030 planning period, based on a high degree of certainty 
that the conservation effort will continue to be implemented and 
effective.
    On the basis of the best scientific and commercial information 
available, we find that the current and future threats are not of 
sufficient imminence, intensity, or magnitude to indicate that the New 
England cottontail is in danger of extinction (endangered), or likely 
to become endangered within the foreseeable future (threatened). 
Therefore, the New England cottontail does not meet the definition of a 
threatened or endangered species, and we are withdrawing our previous 
``warranted, but precluded findings'' and removing the species from the 
list of ``candidate'' species.

Significant Portion of the Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
throughout all or a significant portion of its range. The Act defines 
``endangered species'' as any species which is ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
``threatened species'' as any species which is ``likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range.'' The term ``species'' includes ``any 
subspecies of fish or wildlife or plants, and any distinct population 
segment [DPS] of any species of vertebrate fish or wildlife which 
interbreeds when mature.'' We published a final policy interpreting the 
phrase ``Significant Portion of its Range'' (SPR) (79 FR 37578). The 
final policy states that (1) if a species is found to be endangered or 
threatened throughout a significant portion of its range, the entire 
species is listed as an endangered or a threatened species, 
respectively, and the Act's protections apply to all individuals of the 
species wherever found; (2) a portion of the range of a species is 
``significant'' if the species is not currently endangered or 
threatened throughout all of its range, but the portion's contribution 
to the viability of the species is so important that, without the 
members in that portion, the species would be in danger of extinction, 
or likely to become so in the foreseeable future, throughout all of its 
range; (3) the range of a species is considered to be the general 
geographical area within which that species can be found at the time 
FWS or NMFS makes any particular status determination; and (4) if a 
vertebrate species is endangered or

[[Page 55304]]

threatened throughout an SPR, and the population in that significant 
portion is a valid DPS, we will list the DPS rather than the entire 
taxonomic species or subspecies. As stated above, we find the New 
England cottontail does not warrant listing throughout its range. 
Therefore, we must consider whether there are any significant portions 
of the range of the New England cottontail.
    The SPR policy is applied to all status determinations, including 
analyses for the purposes of making listing, delisting, and 
reclassification determinations. The procedure for analyzing whether 
any portion is an SPR is similar, regardless of the type of status 
determination we are making. The first step in our analysis of the 
status of a species is to determine its status throughout all of its 
range. If we determine that the species is in danger of extinction, or 
likely to become so in the foreseeable future, throughout all of its 
range, we list the species as an endangered (or threatened) species and 
no SPR analysis will be required. If the species is neither in danger 
of extinction nor likely to become so throughout all of its range, we 
determine whether the species is in danger of extinction or likely to 
become so throughout a significant portion of its range. If it is, we 
list the species as an endangered or a threatened species, 
respectively; if it is not, we conclude that listing the species is not 
warranted.
    When we conduct an SPR analysis, we first identify any portions of 
the species' range that warrant further consideration. The range of a 
species can theoretically be divided into portions in an infinite 
number of ways. However, there is no purpose to analyzing portions of 
the range that are not reasonably likely to be significant and 
endangered or threatened. To identify only those portions that warrant 
further consideration, we determine whether there is substantial 
information indicating that (1) the portions may be significant and (2) 
the species may be in danger of extinction in those portions or likely 
to become so within the foreseeable future. We emphasize that answering 
these questions in the affirmative is not a determination that the 
species is endangered or threatened throughout a significant portion of 
its range--rather it is a step in determining whether a more detailed 
analysis of the issue is required. In practice, a key part of this 
analysis is whether the threats are geographically concentrated in some 
way. If the threats to the species are affecting it uniformly 
throughout its range, no portion is likely to warrant further 
consideration. Moreover, if any concentration of threats apply only to 
portions of the range that clearly do not meet the biologically based 
definition of ``significant'' (i.e., the loss of that portion clearly 
would not be expected to increase the vulnerability to extinction of 
the entire species), those portions will not warrant further 
consideration.
    If we identify any portions that may be both (1) significant and 
(2) endangered or threatened, we engage in a more detailed analysis to 
determine whether these standards are indeed met. The identification of 
an SPR does not create a presumption, prejudgment, or other 
determination as to whether the species in that identified SPR is 
endangered or threatened. We must go through a separate analysis to 
determine whether the species is endangered or threatened in the SPR. 
To determine whether a species is endangered or threatened throughout 
an SPR, we will use the same standards and methodology that we use to 
determine if a species is endangered or threatened throughout its 
range.
    Depending on the biology of the species, its range, and the threats 
it faces, it may be more efficient to address the ``significant'' 
question first, or the status question first. Thus, if we determine 
that a portion of the range is not ``significant,'' we do not need to 
determine whether the species is endangered or threatened there; if we 
determine that the species is not endangered or threatened in a portion 
of its range, we do not need to determine if that portion is 
``significant.''
    The threats currently affecting the New England cottontail, without 
consideration for the planned or implemented conservation efforts, are 
occurring throughout the species' range. Habitat loss, predation, and 
the effects of small population size are affecting the species 
relatively uniformly across its range. In addition, the Conservation 
Strategy and its specific actions will continue to be implemented 
throughout the species' range, and we have a high level of certainty 
that those efforts will be effective in addressing the species' 
rangewide threats. Therefore, we find that factors affecting the 
species are essentially uniform throughout its range, indicating no 
portion of the range warrants further consideration of possible 
endangered or threatened status under the Act.
    Our review of the best available scientific and commercial 
information indicates that the New England cottontail is not in danger 
of extinction (endangered) nor likely to become endangered within the 
foreseeable future (threatened), throughout all or a significant 
portion of its range. Therefore, we find that listing the New England 
cottontail as an endangered or threatened species under the Act is not 
warranted at this time.
    We request that you submit any new information concerning the 
status of, or threats to, the New England cottontail to our New England 
Field Office (see ADDRESSES section) whenever it becomes available. New 
information will help us monitor the New England cottontail and 
encourage its conservation. If an emergency situation develops for the 
New England cottontail, we will act to provide immediate protection.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov at Docket Number FWS-R5-ES-2015-0136 and 
upon request from the New England Field Office (see ADDRESSES section).

Author(s)

    The primary author(s) of this document are the staff members of the 
New England Field Office.

Authority

    The authority for this section is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: August 26, 2015.
Daniel M. Ashe,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-22885 Filed 9-11-15; 11:15 am]
BILLING CODE 4310-55-P